Let's talk infectious diseases, the reason for vaccines: ᴮʳᵉᵃᵏᵗʰʳᵒᵘᵍʰ ᴵⁿᶠᵉᶜᵗⁱᵒⁿˢ

 

Just as variants are expected with any virus, so are vaccine breakthrough infections. These breakthroughs can happen for several reasons. A variant, immunocompromised or immunosuppressed individuals, vaccines aren't 100% effective (remember NOTHING is), some people's bodies don't accept vaccines (this is called immunocompetent), and it can just happen without scientific explanation. Regardless of the reason, breakthrough infections are rare but expected. 

A study in Washington state gathered data from over 4 million fully vaccinated people. The data showed a rate of about 1 in 5,000 experienced a breakthrough infection between January 17 and August 21, 2021. More recently, some populations have shown breakthrough infection rates of approximately 1 in 100 fully vaccinated people.

So, if someone is going to get a virus that can be addressed with a vaccine (which, of course, nobody knows if they are going to get it or not) then why bother getting the vaccine? Breakthrough coronavirus infections can cause mild or moderate illness, but the chances of serious COVID-19 are very low, especially for people who are not living with a chronic health condition. The COVID-19 vaccines are very effective in keeping you from having to go to the hospital, being put on a ventilator, or dying due to severe coronavirus disease.

Critics and skeptics might point to the recent death of former U.S. Secretary of State Colin Powell to refute the low occurrence of breakthrough infections in fully vaccinated people. However, Powell was immunocompromised due to battling multiple myeloma as well as Parkinson's, leaving him susceptible to complications. All along scientists and the medical community have made it clear that those who are immunocompromised or immunosuppressed are at greater risk from the virus, but that vaccination does provide a level of protection and is recommended.  

Sources: hopkinsmedicine.org, cdc.gov

Let's talk infectious diseases, the reason for vaccines: ⱽᵃʳⁱᵃⁿᵗˢ

So, let's talk variants. It's a hot topic these days with numerous variants of the COVID-19 virus evolving. Viruses are changing and mutating all the time. It happens when the virus enters our body and makes copies of itself as it spreads from cell to cell. Sometimes the virus makes a mistake and its genetic information is changed slightly as it’s copied. Sometimes those errors cause a disease to fade away; other times, it causes the virus to become more deadly or easily spread.

First, a vocab lesson:

• Mutation:  A mutation refers to a single change in a virus’s genome (genetic code). Mutations happen very frequently, but only sometimes change the characteristics of the virus.
• Lineage: A lineage is a group of closely related viruses with a common ancestor. SARS-CoV-2 has many lineages; all cause COVID-19.
• Variant: A variant is a viral genome (genetic code) that may contain one or more mutations. In some cases, a group of variants with similar genetic changes, such as a lineage or group of lineages, may be designated by public health organizations as a Variant of Concern or a Variant of Interest due to shared attributes and characteristics that may require public health action.

When a variant is suspected it is elevated to being studied in depth. If it is considered to have concerning epidemiological, immunological or pathogenic properties, they graduate to formal investigation. From there, the variants are categorized into the following: 

• Variants Being Monitored (VBM) - which is all variants, literally
• Variant of Interest (VOI) - Possible attributes of a variant of interest:
• Specific genetic markers that are predicted to affect transmission, diagnostics, therapeutics, or immune escape.
• Evidence that it is the cause of an increased proportion of cases or unique outbreak clusters.
• Limited prevalence or expansion in the US or in other countries.

• Variant of Concern (VOC) - Possible attributes of a VOC include those listed for a VOI and the following:
• Evidence of impact on diagnostics, treatments, or vaccines
• Widespread interference with diagnostic test targets
• Evidence of substantially decreased susceptibility to one or more class of therapies
• Evidence of significant decreased neutralization by antibodies generated during previous infection or vaccination
• Evidence of reduced vaccine-induced protection from severe disease
• Evidence of increased transmissibility
• Evidence of increased disease severity
• Variant of High Consequence (VOHC) - Possible attributes of a VOHC include those listed for a VOI and VOC as well as the following:
• Impact on Medical Countermeasures (MCM)
• Demonstrated failure of diagnostic test targets
• Evidence to suggest a significant reduction in vaccine effectiveness, a disproportionately high number of infections in vaccinated persons, or very low vaccine-induced protection against severe disease
• Significantly reduced susceptibility to multiple Emergency Use Authorization (EUA) or approved therapeutics
• More severe clinical disease and increased hospitalizations

As of October 4, 2021 the CDC has 10 VBMs, zero VOIs, and 1 VOC they are looking at in the U.S. The WHO has slightly different tracking methods since they are looking at global outbreaks. The WHO is tracking 15 VBMs, 2 VOIs, and 4 VOCs. Currently, neither organization has any VOHCs.

Because of these expected variants, infectious diseases have the potential to wipe out whole populations of people unless the virus, and its variants, can be stopped or slowed down with very specific measures. 

1) Social distancing/quarantine 

2) Wearing masks 

3) Practicing good hygiene 

4) Vaccines

What about variants and vaccines? Because of ongoing changes, the vaccines we have now will eventually need to be altered to address those changes. Just like the flu shot each year. Based on the top strains the vaccine is altered each year to target those. Scientists believe the coronavirus may end up, at some point, arriving at the same place - the vaccine being altered each year based on the VOCs. 

Sources: who.int, intermountainhealthcare.org, cdc.gov, indianexpress.com

Let's talk infectious diseases, the reason for vaccines: ˢᴬᴿˢ⁻ᶜᵒⱽ⁻²/ᶜᴼⱽᴵᴰ⁻¹⁹/ᶜᵒʳᵒⁿᵃᵛⁱʳᵘˢ

All of us are living this infectious disease in real-time but let's outline the facts...as they are known right now. Because this is a consistently developing virus with mutations and variants there are only some basics we all know for sure.

People with COVID-19 have had a wide range of symptoms reported – ranging from mild symptoms to severe illness. Symptoms may appear 2-14 days after exposure to the virus. Anyone can have mild to severe symptoms. People with these symptoms may have COVID-19:

▪️Fever or chills

▪️Cough

▪️Shortness of breath or difficulty breathing

▪️Fatigue

▪️Muscle or body aches

▪️Headache

▪️New loss of taste or smell

▪️Sore throat

▪️Congestion or runny nose

▪️Nausea or vomiting

▪️Diarrhea

This list does not include all possible symptoms. It gets updated when new symptoms present.

The following are emergency warning signs for COVID-19. If someone is showing any of these signs, seek emergency medical care immediately:

▪️Trouble breathing

▪️Persistent pain or pressure in the chest

▪️New confusion

▪️Inability to wake or stay awake

▪️Pale, gray, or blue-colored skin, lips, or nail beds, depending on skin tone

This list is not all possible symptoms. Call your medical provider for any other symptoms that are severe or concerning to you.

Treatment for COVID depends on the severity of the illness. Most people have mild illness and are able to recover at home. At-home treatment includes: staying home and quarantining from anyone you live with, get rest, stay hydrated, and take over-the-counter medicines to help you feel better. If you have an emergency warning sign (including trouble breathing), call 911. And be honest - disclose your illness so that others can stay protected.

Prevention includes hand-washing (again, were "we" really not doing this before?!), social distancing, wearing masks in highly populated areas, and get vaccinated.

Although most people with COVID-19 get better within weeks of illness, some people experience post-COVID conditions. Post-COVID conditions are a wide range of new, returning, or ongoing health problems people can experience four or more weeks after first being infected with the virus that causes COVID-19. Even people who did not have COVID-19 symptoms in the days or weeks after they were infected can have post-COVID conditions. These conditions can have different types and combinations of health problems for different lengths of time.

Some people are experiencing a range of new or ongoing symptoms that can last weeks or months after first being infected with the virus that causes COVID-19. Unlike some of the other types of post-COVID conditions that only tend to occur in people who have had severe illness, these symptoms can happen to anyone who has had COVID-19, even if the illness was mild, or if they had no initial symptoms. People commonly report experiencing different combinations of the following symptoms:

▪️Difficulty breathing or shortness of breath

▪️Tiredness or fatigue

▪️Symptoms that get worse after physical or mental activities

▪️Difficulty thinking or concentrating (“brain fog”)

▪️Cough

▪️Chest or stomach pain

▪️Headache

▪️Fast-beating or pounding heart

▪️Joint or muscle pain

▪️Pins-and-needles feeling

▪️Diarrhea

▪️Sleep problems

▪️Fever

▪️Lightheadedness

▪️Rash

▪️Mood changes

▪️Change in smell or taste

▪️Changes in period cycles

Some people who had severe illness with COVID-19 experience multiorgan effects or autoimmune conditions over a longer time with symptoms lasting weeks or months after COVID-19 illness. While it is very rare, some people, mostly children, experience multisystem inflammatory syndrome (MIS) during or immediately after a COVID-19 infection. Effects of hospitalization from COVID can also include post-intensive care syndrome, which refers to health effects that begin when a person is in ICU and can remain after a person returns home. These effects can include severe weakness, problems with thinking and judgment, and post-traumatic stress disorder (PTSD).

As the virus spreads, it has new opportunities to change and may become more difficult to stop. These changes can be monitored by comparing differences in physical traits (such as resistance to treatment) or changes in genetic code (mutations) from one variant to another.

Viruses constantly change through mutation, and new variants of a virus are expected to occur. Sometimes new variants emerge and disappear. Other times, new variants persist. Scientists monitor all variants but may classify certain ones as variants of interest, concern, or high consequence based on how easily they spread, how severe their symptoms are, and how they are treated.

𝚅𝚊𝚛𝚒𝚊𝚗𝚝𝚜 𝚘𝚏 𝙲𝚘𝚗𝚌𝚎𝚛𝚗 𝚒𝚗 𝚝𝚑𝚎 𝚄𝚂:

𝙰𝚕𝚙𝚑𝚊 - 𝙱.𝟷.𝟷.𝟽

Spreads much faster than other variants. May potentially cause more people to get sicker and to die. Currently authorized vaccines do work against this variant. Treatments are effective against this variant.

𝙱𝚎𝚝𝚊 - 𝙱.𝟷.𝟹𝟻𝟷

May spread faster than other variants. Current data do not indicate more severe illness or death than other variants. Currently authorized vaccines do work against this variant. Certain monoclonal antibody treatments are less effective against this variant.

𝙶𝚊𝚖𝚖𝚊 - 𝙿.𝟷

Spreads faster than other variants. Current data do not indicate more severe illness or death than other variants. Currently authorized vaccines do work against this variant. Certain monoclonal antibody treatments are less effective against this variant.

𝙳𝚎𝚕𝚝𝚊 - 𝙱.𝟷.𝟼𝟷𝟽.𝟸

Spreads much faster than other variants. May cause more severe cases than the other variants. Infections happen in only a small proportion of people who are fully vaccinated, even with the Delta variant. Preliminary evidence suggests that fully vaccinated people who do become infected with the Delta variant can spread the virus to others. Certain monoclonal antibody treatments are less effective against this variant.

Traditionally it takes 10-15 years to develop, test, and license a vaccine so how was the COVID vaccine created and administered so quickly?

▪️Years of advance research

For 50 years, researchers have been paying attention to related coronaviruses. In this case, SARS-CoV-2 was a new virus, but it belongs to a family of viruses with similar traits. They already knew that the spike protein could be targeted by a vaccine, which gave them a goal to work toward immediately.

▪️A decade of mRNA vaccine research

Researchers have been developing and researching an mRNA vaccine platform for over 10 years. After SARS-CoV-2 was sequenced, it took just a few days to make the mRNA vaccine candidates. More on this platform in a separate post because it is AMAZING!!

▪️Supercharged with funding

The slowest part of vaccine development isn’t finding candidate treatments, but testing them. This often takes years, with companies running efficacy and safety tests on animals and then in humans. Human testing requires three phases that involve increasing numbers of people and proportionately escalating costs. The COVID-19 vaccines went through the same trials, but the billions poured into the process made it possible for companies to take financial risks by running some tests at the same time.

▪️Participants enrolled in the trials quickly

Large scale vaccine clinical trials were organized quickly using networks established in the pursuit of an HIV vaccine. People enrolled quickly due to widespread public interest.

▪️Overlapping phases

Regulators at the FDA and those involved in making these vaccines already had seen scientific results on the mRNA vaccine platform. So researchers could focus their questions on animal models and early human trials so that they were completed more quickly. In some instances, there was an overlap of certain study phases.

▪️Expedited review

As part of its review process, the FDA re-analyzes the data that companies provide. The FDA compressed the review timeline to weeks with people working nights, days, and weekends on parallel teams.

𝙲𝙾𝚅𝙸𝙳 𝙾𝚞𝚝𝚙𝚊𝚝𝚒𝚎𝚗𝚝 𝚃𝚛𝚎𝚊𝚝𝚖𝚎𝚗𝚝𝚜

Currently there are no approved outpatient treatments. There is currently only one FDA approved drug designated for treatment of COVID and it is administered while the patient is still in the hospital.

The antiviral drug Veklury (Remdesivir) is approved for treatment in adult and pediatric patients 12 years of age and older and weighing at least 88 pounds.

Veklury is an anti-viral therapy to combat the coronavirus. It works to block the virus from reproducing by blocking an enzyme that is needed for viruses to replicate.

It is given via IV over the course of 5-10 days and it is given slowly over 30 to 120 minutes once a day. 

Ivermectin tablets are approved by the FDA to treat people with intestinal strongyloidiasis and onchocerciasis, two conditions caused by parasitic worms. In addition, some topical (on the skin) forms of ivermectin are approved to treat external parasites like head lice and for skin conditions such as rosacea.

Some forms of ivermectin are used in animals to prevent heartworm disease and certain internal and external parasites. It’s important to note that these products are different from the ones for people, and safe when used as prescribed for animals, only.

The FDA does. not recommend using ivermectin to attempt to treat COVID-19 for the following reasons:

▪️Ivermectin is not an anti-viral drug and COVID is a virus.

▪️Taking large doses of this drug is dangerous and can cause serious harm.

▪️Never use medications intended for animals on yourself. Ivermectin preparations for animals are very different from those approved for humans. The FDA has received multiple reports of patients who have required medical support and been hospitalized after self-medicating with ivermectin intended for horses.

▪️Even the levels of ivermectin for approved uses can interact with other medications, like blood-thinners. You can also overdose on ivermectin, which can cause nausea, vomiting, diarrhea, hypotension, allergic reactions, dizziness, problems with balance, seizures, coma, and even death.

There’s a lot of misinformation around taking large doses of ivermectin. The FDA reviews drugs not just for safety and effectiveness of the active ingredients, but also for the inactive ingredients. Many inactive ingredients found in animal products aren’t evaluated for use in people. Or they are included in much greater quantity than those used in people. In some cases, we don’t know how those inactive ingredients will affect how ivermectin is absorbed in the human body. (Source: fda.gov)

In May 2021 the FDA issued an emergency use authorization (EUA) for the investigational monoclonal antibody therapy for the treatment of mild-to-moderate COVID-19 in adults and pediatric patients (12 years of age and older weighing at least 88 pounds) with positive COVID results.

Monoclonal antibodies are laboratory-made proteins that mimic the immune system’s ability to fight off harmful antigens such as viruses. Sotrovimab is a monoclonal antibody that is specifically directed against the spike protein of SARS-CoV-2 and is designed to block the virus’ attachment and entry into human cells.

Scientific studies show that high-risk COVID-19 patients treated with monoclonal antibodies were significantly less likely to get very sick and/or need to be hospitalized compared to patients who did not receive the treatments. Studies have also shown that being treated with monoclonal antibodies reduces the risk of getting COVID-19 if you have been exposed to a person testing positive for COVID and you are unvaccinated or partially vaccinated.

{You can find all the sources I used by clicking here.}

Let's talk infectious diseases, the reason for vaccines: ᶻⁱᵏᵃ ⱽⁱʳᵘˢ

The Zika virus is a member of the virus family Flaviviridae and is closely related to other mosquito-borne viruses such as those that cause dengue fever, yellow fever, and Japanese encephalitis. The primary carrier of the virus, the Aedes aegypti mosquito, is unusual in that it is most active during the daytime hours. It only takes one bite for an infection to occur. Once the surrounding skin cells are inoculated, the virus can quickly move into the bloodstream and spread throughout the body.

Zika virus is mainly spread by mosquitoes. The virus can also be transmitted during sex, mostly from men to women as the virus can persist for months in semen.

Zika can also be passed from mother to child during pregnancy and, on rare occasions, through a tainted blood transfusion.

A Zika infection is usually mild and uneventful, but it can turn serious if passed to a developing fetus during the early stages of pregnancy. While scientists do not yet fully understand the pathway of the disease, it appears that the virus is able to breach the placenta during the early part of the first trimester when fetal stem cells are just starting to specialize into the brain, heart, and other vital organs.

The virus' impact on these cells can be devastating, causing serious malformations and increasing the risk of miscarriage and stillbirth. The most serious concern is microcephaly, a rare and irreversible birth defect in which a baby is born with an abnormally small head and brain.

The risk of microcephaly appears to be limited to the first trimester. By the second and third trimesters, the risk will have decreased to near-negligible levels, according to research from the CDC. Still, babies born to mothers with Zika can have serious neurological issues regardless of the trimester she was infected.

While discovered in 1947, Zika virus (ZIKV) remained unimportant and unnoticed until the Yap Island outbreaks in 2007. Even then, it scarcely raised interest and concern quickly abated as the outbreak dwindled without further outbreaks occurring. This situation changed dramatically with the unexpected and large outbreaks that began in 2015 in Brazil—eventually resulting in an estimated 200,000 identified cases. As a result, the world has had to play “catch-up” by rapidly investigating ZIKV immunology, pathophysiology, and its short- and long-term effects, as well as the full spectrum of pathology the virus may cause in different populations.

As of 2021, there is no effective drug to treat—or vaccine to prevent—Zika infection. As of 2019, some 18 known vaccine candidates are in various stages of preclinical and clinical development. A wide variety of formulations are being studied; among those being tested are live virus vaccines, inactivated vaccines, whole-virus vaccines, subunit vaccines, and messenger RNA (mRNA)–, DNA-, protein-, and vector-based formulations.

The ideal vaccine against Zika would require a single dose, be capable of being administered to anyone regardless of age or medical condition (including pregnancy), result in durable (if not lifelong) immunity, prevent medically significant outcomes of infection in both the immediate recipient (eg, GBS) and in the fetus (eg, microcephaly and other congenital conditions), be safe and highly effective, and ideally not require either a cold chain or complex logistics to store and administer. Given the observation of intermittent outbreaks thus far, the ability to store vaccine stockpiles for long periods of time is also necessary.

{You can find all the sources I used by clicking here.}

Let's talk infectious diseases, the reason for vaccines: ᴱᵇᵒˡᵃ ⱽⁱʳᵘˢ

Ebola virus disease (EVD) is a deadly disease with occasional outbreaks that occur mostly on the African continent. EVD most commonly affects people and nonhuman primates. It is caused by an infection with a group of viruses within the genus Ebolavirus.

Ebola virus was first discovered in 1976 near the Ebola River in the Democratic Republic of Congo. Since then, the virus has been infecting people from time to time, leading to outbreaks in several African countries. Scientists do not know where Ebola virus comes from. Based on similar viruses, they believe EVD is animal-borne, with bats or nonhuman primates being the most likely source.

The virus first spreads to people through direct contact with the blood, body fluids and tissues of animals. Ebola virus then spreads to other people through direct contact with body fluids of a person who is sick with or has died from EVD. The virus then gets into the body through broken skin or mucous membranes in the eyes, nose, or mouth. People can get the virus through sexual contact with someone who is sick with or has recovered from EVD. The virus can persist in certain body fluids, like semen, after recovery from the illness.

Symptoms may appear anywhere from 2 to 21 days after contact with the virus, with an average of 8 to 10 days. The course of the illness typically progresses from “dry” symptoms initially (such as fever, aches and pains, and fatigue), and then progresses to “wet” symptoms (such as diarrhea and vomiting) as the person becomes sicker.

Primary signs and symptoms of Ebola often include:

▪️Fever

▪️Aches and pains, such as severe headache and muscle and joint pain

▪️Weakness and fatigue

▪️Sore throat

▪️Loss of appetite

▪️Gastrointestinal symptoms including abdominal pain, diarrhea, and vomiting

▪️Unexplained hemorrhaging, bleeding or bruising

▪️Other symptoms may include red eyes, skin rash, and hiccups (late-stage).

There are currently two treatments approved to treat EVD caused by the Ebola virus. Both treatments use monoclonal antibodies to treat the disease. Ebola virus disease has no cure.

Vaccine development began in the late 1970s. Because EVD outbreaks are rare and have, until 2014, been controlled quickly, commercial vaccine manufacturers have demonstrated little urgency in advancing vaccines through clinical trials. That changed in 2014 with an uncontrolled outbreak.

In 2019 the first Ebola vaccine was approved for use. This vaccine is given as a single dose vaccine and has been found to be safe and protective against Zaire ebolavirus, which has caused the largest and most deadly Ebola outbreaks to date.

{You can find all the sources I used by clicking here.}

Let's talk infectious diseases, the reason for vaccines: ᴴᵘᵐᵃⁿ ᵖᵃᵖⁱˡˡᵒᵐᵃᵛⁱʳᵘˢ ⁽ᴴᴾⱽ⁾

Human papillomavirus (HPV) is a group of more than 200 viruses that cause warts. Roughly 40 of these variants are transmitted sexually and cause warts on or around your genitals, anus, mouth, or throat. Some can cause different types of cancer.

Most HPV infections don't lead to cancer. But some types of genital HPV can cause cancer of the lower part of the uterus that connects to the vagina (cervix). Other types of cancers, including cancers of the anus, penis, vagina, vulva and back of the throat (oropharyngeal), have been linked to HPV infection.

In most cases, your body's immune system defeats an HPV infection before it creates warts. When warts do appear, they vary in appearance depending on which kind of HPV is involved. There are four kinds of warts: genital, common, plantar, and flat.

The most frequent symptom of HPV infection is actually no symptoms at all. A lack of symptoms is especially true for the high-risk strains of HPV. That is why it is so important to see your gynecologist regularly for exams and appropriate screening tests.

If you do develop symptoms of HPV infection it is likely because you have developed genital warts from the virus.

Nearly all cervical cancers are caused by HPV infections, but cervical cancer may take 20 years or longer to develop after an HPV infection. Because early cervical cancer doesn't cause symptoms, it's vital that women have regular screening tests to detect any precancerous changes in the cervix that might lead to cancer.

At the current time, we only have approved and reliable screening testing for the detection of genital tract HPV in women.

HPV is so common that almost every sexually active person will eventually get it if not vaccinated. According to the CDC, there were 43 million HPV infections in 2018.

The HPV vaccine was first developed by the University of Queensland (Australia) by Professors Ian Frazer and Jian Zhou. In 1990, Frazer and Zhou began to synthesize particles that mimicked HPV, from which the vaccine would later be made. These particles are called “virus-like particles” (VLPs), and are small particles that contain proteins from the outer layer of the HPV virus. VLPs do not contain any of the DNA, dead or live, from the virus, and therefore cannot cause an HPV infection or related cancer. Introducing these VLPs into the body via injection stimulates the body to create the antibodies needed to fight it and clear it from the body. As the VLP closely resembles the actual virus, these antibodies will attack and remove HPV if it enters the body. This method of vaccination is highly effective, as the VLPs cause high levels of antibody production.

In 1991, Frazer and Zhou’s findings were first presented to the scientific community. After seven years of design and testing, the first human trials for the vaccine, named Gardasil, were completed. This vaccine prevented four high-risk HPV types (HPV 6, 11, 16, and 18), which would target over 70% of cervical cancer cases. In 2006, following extensive clinical trials which found the vaccine to provide almost 100% protection against HPV 16 and 18, the vaccine was approved for use by Australia and the USA, and by 2007 the vaccine was approved in 80 countries. Since then, two further vaccines have been approved and are used worldwide.

{You can find all the sources I used by clicking here.}

Let's talk infectious diseases, the reason for vaccines: ᴿᵒᵗᵃᵛⁱʳᵘˢ

Rotavirus is present in stool and is mainly transmitted between hand and mouth contact. It’s highly contagious and easily transmittable. While it occurs most often in young children, adults can also get the infection, although it’s usually less severe.

If you touch a person or object carrying the virus and then touch your mouth, you could develop the infection. This is most common from not washing your hands after using the toilet or changing diapers. The virus can also remain on surfaces for several days (and possibly weeks) after an infected person touches them. This is why it’s crucial to disinfect all common surfaces in your home frequently, especially if a member of your household has rotavirus.

People who are infected with rotavirus shed the virus in their stool. This is how the virus gets into the environment and can infect other people. People shed rotavirus the most, and are more likely to infect others, both when they have symptoms and during the first three days after they recover. People with rotavirus can also infect others before they have symptoms.

The most common symptoms of rotavirus are severe watery diarrhea, vomiting, fever, and/or abdominal pain. Symptoms usually start about two days after a person is exposed to rotavirus. Vomiting and watery diarrhea can last three to eight days. Additional symptoms may include loss of appetite and dehydration (loss of body fluids), which can be especially dangerous for infants and young children.

Dehydration is the greatest concern in children. This age group is more vulnerable to a loss of fluid and electrolytes through vomiting and diarrhea because of they have smaller body weights.

The rotavirus isn’t treated with medications. It usually resolves on its own with time. Rotavirus vaccine is the best way to protect your child against rotavirus disease.

In 1973, a team of Australian researchers examining the intestinal tissues and feces of children with diarrhea through electron micrography discovered the presence of a novel wheel-shaped virus fragment. This virus was given the name “rotavirus” after the Latin word for wheel - rota.

By 1980, the CDC had declared rotavirus to be the most frequent cause of serious gastrointestinal illness in infants and toddlers and estimated that the virus caused between 20 and 60 deaths annually in the United States. It was also estimated to cause 400,000 physician visits, 200,000 emergency room visits, and between 55,000 and 70,000 hospitalizations. It was still not known exactly how the virus was spread but it was assumed that it occurred through the fecal-oral route.

By 1983, research priorities included the development of a test that could rapidly identify the specific virus, the establishment of a universal classification for each group and type of rotavirus, and the development of a vaccine against the virus.

The first vaccine for rotavirus, RotaShield, was licensed and recommended for routine childhood immunization in 1998. However, it was withdrawn in 1999 due to safety concerns. Scientists associated the vaccine with a rare intestinal problem called intussusception, a potentially fatal telescoping of part of the bowel. Back to the drawing board!

In 2006 the second vaccine was licensed for use and proved successful.

Since the vaccine was introduced, hospitalizations and deaths from rotavirus have dropped significantly. Most children (about 9 out of 10) who get the vaccine will be protected from severe rotavirus disease. About 7 out of 10 children will be protected from rotavirus disease of any severity.

Two rotavirus vaccines are currently licensed for infants in the United States. Both are administered through oral drops.

{You can find all the sources I used by clicking here.}

Let's talk infectious diseases, the reason for vaccines: ⱽⁱʳᵃˡ ᴴᵉᵖᵃᵗⁱᵗⁱˢ

Hep A

Hepatitis A is a liver infection caused by the hepatitis A virus (HAV). HAV is found in the stool and blood of people who are infected. Hep A is very contagious. It is spread when someone unknowingly ingests the virus — even in microscopic amounts — from an infected person or through eating contaminated food or drink. Symptoms of hep A can last up to 2 months and include fatigue, nausea, stomach pain, and jaundice. Most people with hep A do not have long-lasting illness.

Hep B

Hepatitis B is a liver infection caused by the hepatitis B virus (HBV). Hep B is spread when blood, semen, or other body fluids from a person infected with the virus enters the body of someone who is not infected. This can happen through sexual contact; sharing drug-injection equipment; or from mother to baby at birth. Possible symptoms can include fatigue, poor appetite, stomach pain, nausea, and jaundice. For many people, hep B is a short-term illness. For others, it can lead to serious, even life-threatening health issues like cirrhosis or liver cancer.

Hep C

Hepatitis C is a liver infection caused by the hepatitis C virus (HCV). Hep C is spread through contact with blood from an infected person. Today, most people become infected with the hep C virus by sharing drug-injection equipment. For some people, hep C is a short-term illness, but for more than half of people who become infected with the hepatitis C virus, it becomes a long-term, chronic infection. Chronic hep C can result in serious, even life-threatening health problems like cirrhosis and liver cancer. People with chronic hepatitis C can often have no symptoms and don’t feel sick. When symptoms appear, they often are a sign of advanced liver disease.

Hepatitis D only occurs in people who are also infected with the hepatitis B virus. Hepatitis E is a rare liver infection hardly occurring in developed countries.

If you are diagnosed with viral hepatitis or any other form of hepatitis, you will generally be referred to either a gastroenterologist, who specializes in diseases of the digestive tract (including the liver), or a hepatologist, who specializes solely in diseases of the liver.

Dr. Maurice Hilleman spent decades researching and investigating viral hepatitis.

In 1981 he created a human-blood-derived hepatitis B vaccine, Heptavax-B. It was the first subunit viral vaccine developed in the United States. The vaccine proved effective at preventing hepatitis B. But, because of concerns about HIV infection, it was superseded in 1986 by a product that did not use human serum. Dr. Hilleman replaced human blood products used in the 1981 vaccine with an enzyme to remove the virus’s surface protein. The yeast-derived surface protein produced immunity to the hepatitis B virus.

Hilleman was one of the first scientists to detect the hepatitis A virus and its antibodies. Tests in 1992 showed that the vaccine was 100% effective in preventing the disease. So in 1995 the FDA approved it for licensed use.

Vaccines are available, and recommended, for prevention of Hepatitis A & B. Hepatitis C does not need vaccination, Hepatitis D is prevented through the vaccine for Hep B, and Hepatitis E is not vaccinated for in the United States or other developed countries.

{You can find all the sources I used by clicking here.}

Let's talk infectious diseases, the reason for vaccines: ᴹᵉⁿⁱⁿᵍᵒᶜᵒᶜᶜᵃˡ ᵈⁱˢᵉᵃˢᵉ

Meningococcal disease is any illness caused by the bacteria Neisseria meningitidis, also known as meningococcus. These illnesses include meningitis and bloodstream infections (bacteremia or septicemia). There are six types of Neisseria meningitidis — A, B, C, W, X, and Y — that cause most disease worldwide. Three of these serogroups (B, C, and Y) cause most of the illness seen in the United States.

These bacteria spread through the exchange of respiratory and throat secretions like spit (e.g., by living in close quarters, kissing). The bacteria causes two major infections: Meningococcal Meningitis and Meningococcal Septicemia (aka Meningococcemia).

When someone has meningococcal meningitis, the bacteria infect the lining of the brain and spinal cord and cause swelling. Symptoms include:

▪️Fever

▪️Headache

▪️Stiff neck

▪️Nausea

▪️Vomiting

▪️Photophobia (eyes being more sensitive to light)

▪️Altered mental status (confusion)

When someone has meningococcal septicemia, the bacteria enter the bloodstream and multiply, damaging the walls of the blood vessels. This causes bleeding into the skin and organs. Symptoms include:

▪️Fever and chills

▪️Fatigue

▪️Vomiting

▪️Cold hands and feet

▪️Severe aches or pain in the muscles, joints, chest, or abdomen (belly)

▪️Rapid breathing

▪️Diarrhea

▪️In the later stages, a dark purple rash

Meningococcal disease can be difficult to diagnose because the signs and symptoms are often similar to those of other illnesses. Doctors treat meningococcal disease with a number of antibiotics. It is important that treatment start as soon as possible as these diseases are severe and can be deadly.

Depending on how serious the infection is, people with meningococcal disease may need other treatments, including:

▪️Breathing support

▪️Medications to treat low BP

▪️Surgery to remove dead tissue

▪️Wound care for parts of the body with damaged skin

Even with antibiotic treatment, 10 to 15 in 100 people infected with meningococcal disease will die. Up to 1 in 5 survivors will have long-term disabilities, such as loss of limb(s), deafness, nervous system problems, or brain damage.

In 1974 a new approach to vaccine science was introduced through a series of meningococcal polysaccharide vaccines developed by Maurice Hilleman and his team.

Polysaccharide vaccines did not use live or attenuated pathogens, but rather the polysaccharide (complex sugar) outer coating of these bacteria.

The first vaccine -- meningococcal polysaccharide vaccine or MPSV4 -- was approved in 1978. An improved vaccine, the meningococcal conjugate vaccine or MCV4 was approved in 2005. It uses antigens taken from the polysaccharide capsule and then bound to a separate protein that targets the body's immune cells. This makes it easier for the body's immune system to see and recognize the antigens. Both vaccines protect against four types of meningococcal disease. In 2015, two serogroup B vaccines were given approval and protect against the other two forms of meningococcal disease.

All of these vaccines are about 85-90% effective in preventing meningococcal disease.

{You can find all the sources I used by clicking here.}

Let's talk infectious diseases, the reason for vaccines: ᴾᵒˡⁱᵒ ⁽ᴾᵒˡⁱᵒᵐʸᵉˡⁱᵗⁱˢ⁾

Polio is caused by the aptly named poliovirus. The poliovirus only occurs in humans. Polio is commonly known as a crippling disease that spreads from person to person, causing paralysis of muscles as a result of the virus invading the brain and spinal column of the person infected. It is highly contagious disease that is spread from person to person by several methods or modes of transmission. 

Transmission methods include:

▪️Fecal-oral transmission - When the feces of an infected person is introduced (via the mouth) to another person, the disease is transmitted. This commonly occurs when there is contamination of drinking water or food.

▪️Droplet spread - this mode is less common than fecal-oral transmission.

▪️Direct contact

▪️Oral to Oral

▪️Contact with an object (such as a toy) contaminated with an infected person’s stool/feces or saliva/droplet spread, that is put into the mouth.

Once contracted, the contagious virus resides in the infected person’s intestines and throat. There are two kinds of polio, non-paralytic and paralytic.

Non-paralytic polio symptoms go away without any type of intervention, they may include:

▪️Sore throat

▪️Fever

▪️Fatigue

▪️Stomach discomfort

▪️Nausea

▪️Headache

Of the total number of those infected with the polio virus, a smaller number will develop serious symptoms—such as those involving the nervous system. The symptoms, which are considered the most serious may begin mimicking non-paralytic polio but then there is a progression to more serious symptoms such as:

▪️Loss of reflexes

▪️Severe muscle aches

▪️Flaccid paralysis

▪️Paresthesia

▪️Meningitis, which occurs in one in 25 people with polio according to the CDC

▪️Paralysis or weakness in the arms and/or legs, which occurs in about one in 200 people with polio, according to the CDC

▪️Death (from the paralysis of muscles that are required for breathing)

Paralytic polio can cause long-term or permanent paralysis of muscles, disability (such as being unable to walk without crutches), bone deformities, or death.

There is no known effective treatment for polio, other than palliative treatment and prevention of complications. Supportive treatment may include:

▪️Ventilators (to enable normal breathing)

▪️Pain medication

▪️Physical therapy (to prevent loss of muscle function)

𝙿𝚘𝚜𝚝-𝚙𝚘𝚕𝚒𝚘 𝚂𝚢𝚗𝚍𝚛𝚘𝚖𝚎

Post-polio syndrome (PPS) is a condition that can affect polio survivors decades after they recover from their initial poliovirus infection. Unlike poliovirus, PPS is not contagious. PPS affects between 25 and 40 out of every 100 polio survivors.

Symptoms of post-polio syndrome may include:

▪️Muscle or joint weakness and pain which progressively worsens

▪️Fatigue (physical and mental)

▪️Atrophy of muscles (wasting)

▪️Problems swallowing or breathing

▪️Apnea or other sleep-related breathing disorders

▪️Inability to tolerate cold temperatures

Some people with PPS have only minor symptoms, while others develop more visible muscle weakness and atrophy. PPS is rarely life-threatening, but the symptoms can make it difficult for an affected person to function independently.

Although major polio epidemics were unknown before the 20th century, polio survived quietly as an endemic pathogen until the 1900s when major epidemics began to occur in Europe. Soon after, widespread epidemics appeared in the United States. By 1910, frequent epidemics became regular events throughout the developed world primarily in cities during the summer months. At its peak in the 1940s and 1950s, polio would paralyze or kill over half a million people worldwide every year.

In 1908, Vienna MDs Landsteiner and Popper announced that the infectious agent in polio was a virus. They deduced the viral nature of polio by carefully filtering preparations of spinal cord fluid from a person who had died of polio. The filters trapped bacteria so The researchers then concluded that an infectious particle smaller than bacteria caused the disease. Poliovirus itself would not be visible to researchers until the 1950s, when the electron microscope was available.

Early polio vaccine trials were disastrous. Several subjects died of polio, and many were paralyzed, made ill, or suffered allergic reactions to the vaccines. In 1941, researchers discovered that polio wasn't just a disease of the nervous system but also in the digestive system. This finding gave hope that a vaccine could be developed that would produce antibodies to fight the virus in the bloodstream before it reached the nervous system.

In 1949, further research revealed that there were no more than three immunologically different types of polio. This was an important finding because a vaccine would have to produce immunity to all poliovirus types.

Within the quest to develop a vaccine, researchers were investigating the idea of using human immunoglobulin (IgG, or gamma globulin) to protect people from polio. IgG is an antibody preparation made from blood pooled from many people who most likely have antibodies to common infections. Their disease-specific antibodies in the IgG, when injected into a person who had recently or would soon be exposed to the disease, had been shown to provide protection. This type of protection is known as passive immunization. Three clinical trials in 1951-52 showed some likely protective effects of gamma globulin use against polio. Use of the preparation presented several problems, though. Gamma globulin was expensive to produce and it gave only temporary protection. It would need to be used again in each subsequent epidemic. Moreover, physicians relied on gamma globulin for protection against measles, hepatitis, and other diseases for which there were no vaccines. The supply was limited, and the need was great.

A vaccine was still the ideal treatment. In 1954, Jonas Salk conducted a massive clinical trial with his version of a polio vaccine. When the results were studied in 1955 it found that his version of the vaccine was 80-90% effective against paralytic polio. The same day those findings were released to the public, the vaccine was approved for use and vaccinations started immediately. However, within a short amount of time vaccinations were halted after adverse reactions, such as paralysis, were occurring in children. One of the labs in California producing the vaccine were skipping a step that was vital to the safety of the vaccine. Standards were reset and procedures solidified and production started back up.

Jonas Salk's polio vaccine was IPV, an Inactivated Polio Vaccine, and therefore administered via a needle. But there were others who thought they could avoid administration from a needle and hit the digestive system faster if it was given orally.

1959 found the Soviet exploring the polio vaccine orally. Albert Sabin had spent years studying and attenuating the three types of polioviruses so that they were effective in inducing immunity to polio but weak enough not to cause disease. Sabin's oral polio vaccine (OPV) was fed to 10 million Soviet children.

The OPV had several advantages over the Salk vaccine (IPV).

▪️It produced an immune response faster than Salk’s vaccine, which meant that it could be used to respond to an epidemic.

▪️Because it entered the mouth, it traveled through the digestive system in the same manner as the wild virus. Vaccine recipients shed weakened vaccine virus in their stools, which sometimes had the effect of weakly immunizing those around them.

▪️OPV, often delivered on a sugar cube and eaten, was easier to give than the Salk vaccine, which was injected.

The IPV, however, retained one major advantage over the OPV: The killed viruses in IPV cannot revert to virulent forms as can the viruses in OPV.

Other differences between the two vaccines include:

▪️ The OPV does not require a trained health worker to administer it, the IPV does require one.

▪️ The IPV strengthens the immune system and provides further protection from polio. It is for this reason that IPV is usually given in addition to OPV in certain countries.

Sabin's OPV was licensed for use in the United States in 1960, and it protected against Type 1 polio. In 1963 a vaccine would be licensed that protected against all three types, which was the goal.

Salk's IPV vaccine was phased out of use in 1968 and phased back in to use in 1997 when an improved version was developed. By the year 2000, the United States had returned to using Salk's IPV exclusively due to concerns over OPV causing cases of polio. OPV is still used in some parts of the world.

{You can find all the sources I used by clicking here.}

Let's talk infectious diseases, the reason for vaccines: ᴵⁿᶠˡᵘᵉⁿᶻᵃ

There are four types of influenza viruses: A, B, C and D. Human influenza A and B viruses cause seasonal epidemics of disease (known as the flu season) almost every winter in the United States. Influenza A viruses are the only influenza viruses known to cause flu pandemics, i.e., global epidemics of flu disease. A pandemic can occur when a new and very different influenza A virus emerges that both infects people and has the ability to spread efficiently between people. Influenza type C infections generally cause mild illness and are not thought to cause human flu epidemics. Influenza D viruses primarily affect cattle and are not known to infect or cause illness in people.

Influenza A viruses are found in humans and in many different animals, including ducks, chickens, pigs, whales, horses, seals, and cats. Influenza B viruses circulate widely only among humans.

The influenza virus infects the nose, lungs, and throat. It spreads when an infected person coughs, sneezes, or talks in the presence of other people. Droplets containing the virus may come into contact with a person via their mouth, nose, or eyes, and then cause infection. According to the CDC, the best evidence is that influenza is usually spread by large droplet transmission, which can occur within six feet of an individual.

Touching a surface and then touching your mouth, nose, or eyes may also transmit the flu. The virus may end up on a surface due to respiratory droplets or hands contaminated by respiratory secretions. Social interactions such as shaking hands can transmit the virus in this way as well.

Common symptoms include the following:

▪️ Fever and chills

▪️ Exhaustion

▪️ Aches and Pains

▪️ Coughing

▪️ Headache

▪️ Congestion

Vomiting and diarrhea are not common flu symptoms for most people, but some do experience them. Children are more likely to have vomiting and diarrhea with influenza than adults.

If vomiting and diarrhea are your primary and most significant symptoms, you probably have a stomach bug (sometimes referred to as the stomach flu, though it is not influenza) instead.

In the deadly Spanish influenza pandemic of 1918-19, investigators attempted to develop vaccines to prevent influenza, though they had not yet correctly identified the causative pathogen. These vaccines would certainly not have prevented influenza infection--as we know now, the pandemic was caused by a new strain of the influenza A virus. Influenza viruses would not be isolated and identified until the 1930s, and the first commercial influenza vaccines were not licensed in the United States until the 1940s.

By the end of 1940 researchers had figured out that there were several different influenza viruses so vaccine development had to take that discovery into consideration. In 1945, the first influenza vaccine was approved for military use in the United States. It was approved the next year for civilian use. Influenza vaccine development was a high priority for the U.S. military after the deaths of approximately 1 in every 67 soldiers from influenza during the 1918-1919 pandemic.

As new strains were discovered, vaccines were altered and developed to provide protection against the worst strains. The seasonal flu vaccine protects against the influenza viruses that research indicates will be most common during the upcoming season.

Every flu season is different, and influenza infection can affect people differently, but millions of people get flu every year, hundreds of thousands of people are hospitalized and thousands to tens of thousands of people die from flu-related causes every year. An annual seasonal flu vaccine is the best way to help protect against flu.

{You can find all the sources I used by clicking here.}

Let's talk infectious diseases, the reason for vaccines: ᶜʰⁱᶜᵏᵉⁿᵖᵒˣ/ˢʰⁱⁿᵍˡᵉˢ ⱽᵃᶜᶜⁱⁿᵉ

Until 1767 people didn't know that there were two different kinds of pox - small and chicken. But in 1767 English physician William Heberden was the first to give a detailed description of the differences between the two.

In 1953, Thomas Weller, MD isolated the varicella virus from cases of chickenpox and shingles. But it wasn't until 1974 that a live strain of the virus was successfully attenuated for vaccine production. And then it seems like everything stalled...at least in the United States. A vaccine wasn't licensed for use in the US until 1995.

The vaccine for shingles was first approved for use in the US in 2006 in adults 60 and older. In 2017 the recommendation was revised to include healthy adults 50 and older.

{You can find all the sources I used by clicking here.}

Let's talk infectious diseases, the reason for vaccines: ˢʰⁱⁿᵍˡᵉˢ ⁽ᴴᵉʳᵖᵉˢ ᶻᵒˢᵗᵉʳ⁾

Shingles is caused by the same virus that causes chickenpox, a member of the herpes family of viruses. After a person has chickenpox, the virus can live dormant in the nervous system in nerve fibers for life. Sometimes the virus remains dormant forever, but in other cases, the virus re-emerges or reactivates. The causes of reactivation include: disease, stress, or aging. About 98% of US adults have had chickenpox and are at risk for shingles.

It inflames sensory nerves and can result in severe pain. It causes localized pain, numbness, and itching, followed by the appearance of clustered blisters in a strip pattern on one side of the body. Sometimes the pain can persist for weeks, months, or years after the rash heals (known as post-herpetic neuralgia). Other symptoms include: fever, headache, chills, upset stomach, muscle weakness, skin infection, scarring, fatigue, and decrease or loss of vision or hearing.

Because the pain from shingles is localized, it can be mistaken for other conditions depending on where it's focused. For example, a stabbing or persistent pain on one side of the lower back may be attributed to sciatica or a kidney problem when, in fact, it's the early sign of a shingles outbreak of the leg. Similarly, shingles pain around the lips could suggest a cold sore coming on, while pain focused on the eye or ear might seem like the start of a migraine.

Aside from the discomfort that can come along with shingles, it is particularly concerning because of its potential complications.

The most common complication of shingles is a potentially debilitating condition called postherpetic neuralgia (PHN) that develops when nerve fibers become damaged. It's characterized by persistent pain in the area where a shingles rash has been. Treating PHN can be complicated, but it's important, as the condition can lead to further complications such as depression, fatigue, trouble concentrating, sleep issues, and appetite loss. There's no one-size-fits-all approach, however, and it often takes several medications to relieve the pain and other symptoms.

The only prevention for shingles is a vaccine.

{You can find all the sources I used by clicking here.}

Let's talk infectious diseases, the reason for vaccines: ᶜʰⁱᶜᵏᵉⁿ ᴾᵒˣ ⁽ⱽᵃʳⁱᶜᵉˡˡᵃ⁾

Chickenpox is caused by the highly contagious varicella zoster virus. Varicella is a herpes virus, putting it in the same family as the organisms that cause infections such as genital herpes and cold sores or fever blisters. Unlike other viruses, after a bout of chickenpox is over, the varicella virus hangs around in the nervous system rather than disappearing from the body.

Viruses such as varicella make people sick by invading healthy cells and using them to multiply, so when the body's immune system detects the presence of a virus in the body, it kicks into action, setting off symptoms that can be unpleasant but are designed to fight off infection. So, although a specific virus is the cause of chickenpox infection, the symptoms are brought on by the unique way the immune system responds to the virus.

It is characterized by itchy red blisters that appear all over the body. It is spread by coughing and sneezing, and by direct contact with blisters. The infection will have to be in your body for around seven to 21 days before the rash and other symptoms develop. You start to be contagious to those around you up to 48 hours before the skin rash starts to occur.

The non-rash symptoms may last a few days and include:

▪️fever

▪️headache

▪️loss of appetite

One or two days after you experience these symptoms, the classic rash will begin to develop. The rash goes through three phases before you recover. These include:

▪️You develop red or pink bumps all over your body.

▪️The bumps become blisters filled with fluid that leaks.

▪️The bumps become crusty, scab over, and begin to heal.

The bumps on your body will not all be in the same phase at the same time. New bumps will continuously appear throughout your infection. The rash may be very itchy, especially before it scabs over with a crust.

You are still contagious until all the blisters on your body have scabbed over. The crusty scabbed areas eventually fall off. It takes seven to 14 days to disappear completely.

{You can find all the sources I used by clicking here.}

Let's talk infectious diseases, the reason for vaccines: ᴴᵃᵉᵐᵒᵖʰⁱˡᵘˢ ⁱⁿᶠˡᵘᵉⁿᶻᵃᵉ ᵗʸᵖᵉ ᵇ ⁽ᴴⁱᵇ⁾

Despite its name, Haemophilus influenzae type b – or Hib – doesn’t cause influenza. In the 1890s, doctors thought this bacteria might cause flu and – despite later research showing flu is caused by a virus – the name stuck. So what is it?

Haemophilus influenzae disease is a name for any infection caused by bacteria called H. influenzae. These bacteria live in people’s nose and throat, and usually cause no harm. However, the bacteria can sometimes move to other parts of the body and cause infection.

People spread H. influenzae, including Hib, to others through respiratory droplets. This happens when someone who has the bacteria in their nose or throat coughs or sneezes. People who are not sick but have the bacteria in their noses and throats can still spread the bacteria. Experts do not know how long it takes after H. influenzae enter a person’s body for someone to get sick. However, it could take as little as a few days before symptoms appear.

Hib bacteria can cause many types of invasive disease, including meningitis, pneumonia, cellulitis (skin infection), septic arthritis (joint infection), bloodstream infection, and epiglottitis (infection causing obstruction or closing of the windpipe). Prior to 1985 Hib disease was the leading cause of bacterial meningitis among U.S. children under 5 years old. Hib can also cause mild infections like bronchitis or ear infections.

Symptoms depend on the part of the body that is infected. Treatment depends on the kind of infection. Depending on how serious the infection is, people with H. influenzae disease may need care in a hospital. Even with appropriate treatment, some H. influenzae infections can result in long-term problems or death. For example, bloodstream infections can result in loss of limbs. Meningitis can cause brain damage or hearing loss.

In 1892, German physician Richard Pfeiffer isolated a bacterium from the lungs and sputum of influenza patients during a pandemic. Pfeiffer believed that he had found the cause of influenza. However, in the 1930s it was established that influenza is caused by a virus, not bacteria. But the bacteria Pfeiffer had isolated did prove to be useful in identifying several diseases.

In 1931, American researcher Margaret Pittman, PhD classified different types of Haemophilus influenzae bacteria and found that type b (called Hib) caused nearly all cases of Haemophilus influenzae meningitis. It would later be confirmed that Hib could also cause many other serious diseases, including infections of the blood, bone, and joints.

The first vaccine against Hib disease was licensed in the United States in 1985 and was used until 1988. It was replaced by the first conjugate vaccine against Hib. Today there are three conjugate Hib disease vaccines available in the United States, as well as two combination vaccines that provide protection against multiple diseases, including Hib disease.

With widespread use of the vaccine, the number of reported cases of invasive Hib disease in US children has been reduced by 99%.

{You can find all the sources I used by clicking here.}

Let's talk infectious diseases, the reason for vaccines: ᵀᵘᵇᵉʳᶜᵘˡᵒˢⁱˢ ⁽ᵀᴮ⁾

Tuberculosis (TB) is a contagious airborne disease caused by Mycobacterium tuberculosis, a bacterium that grows and divides inside of cells.

There are two kinds of TB, latent and active.

𝙻𝚊𝚝𝚎𝚗𝚝 𝚃𝙱

In most people, the immune system can contain the bacteria so that they do not replicate and cause disease. In this case, a person will have TB infection but not active disease.

Doctors refer to this as latent TB. A person may never experience symptoms and be unaware that they have the infection. There is also no risk of passing on a latent infection to another person. However, a person with latent TB still requires treatment. About 5% to 10% of infected people who do not receive treatment for latent TB infection will develop TB disease (active TB) at some time in their lives.

The CDC estimate that as many as 13 million people in the U.S. have latent TB.

𝙰𝚌𝚝𝚒𝚟𝚎 𝚃𝙱

The body may be unable to contain TB bacteria. This is more common when the immune system is weakened due to illness or the use of certain medications. When this happens, the bacteria can replicate and cause symptoms, resulting in active TB. People with active TB can spread the infection.

The infection, which starts in the lungs, causes nodules known as tubercles, or Ghon focii, which are spots left by dead infected tissue. With time, the disease can spread to other areas of the lung and larger areas of lung tissue may die off, causing cavities. Bacteria can also spread to other organs, including the kidney, brain, and spine.

The signature symptom of active TB is a bad cough that produces blood-tinged phlegm and can last three or more weeks. Other symptoms include chest pain, fatigue, loss of appetite, weight loss, fever, chills, and night sweats. Symptoms typically worsen over time, but they can also spontaneously go away and return.

TB usually affects the lungs, though symptoms can develop in other parts of the body. This is more common in people with weakened immune systems. TB can also cause:

▪️persistently swollen lymph nodes, or “swollen glands”

▪️abdominal pain

▪️joint or bone pain

▪️confusion

▪️a persistent headache

▪️seizures

People should ask for a TB test if they:

▪️have spent time with a person who has or is at risk of TB

▪️have spent time in a country with high rates of TB

▪️work in an environment where TB may be present

Two tests can show whether TB bacteria are present:

▪️the TB skin test

▪️the TB blood test

However, these cannot indicate whether TB is active or latent. To test for active TB disease, the doctor may recommend a sputum test and a chest X-ray.

Everyone with TB needs treatment, regardless of whether the infection is active or latent.

The right type of antibiotic and length of treatment will depend on:

▪️the person’s age and overall health

▪️whether they have latent or active TB

▪️the location of the infection

▪️whether the strain of TB is drug-resistant

Treatment for latent TB can vary. It may involve taking an antibiotic once a week for 12 weeks or every day for 9 months.

Treatment for active TB may involve taking several drugs for 6–9 months. When a person has a drug-resistant strain of TB, the treatment will be more complex.

TB is not something that is typically vaccinated against in the United States and it can be fatal if left untreated.

TB has been around for tens of thousands of years. It was often called "consumption" because of the dramatic weight loss it can cause. Before the 1940s, when the antibiotic streptomycin became available, there wasn't much that could be done for the illness. Fresh air, good nutrition, and sunlight were thought to be helpful but didn't always work. In some cases, doctors attempted to remove a diseased lung. From the 17th through the 19th centuries, it is believed that one in five people died from tuberculosis.

It wasn't until 1882 that TB was identified. Robert Koch isolated and cultured Mycobacterium tuberculosis. He immediately began to work on a vaccine for treatment and prevention of tuberculosis.

Between 1904 and 1921 Albert Calmette and Camille Guérin worked on attenuated tuberculosis bacilli to test on humans. They used TB from cows to weaken the bacteria enough to place in humans in hopes of providing some immunity. Their preparation is called Bacillus Calmette-Guérin, or BCG in shorthand.

In 1928, the Health Committee of the League of Nations adopted BCG as a recommended tuberculosis vaccine. Between 1947 and 1951 a total of 8 million babies and nearly 14 million people were given the BCG vaccine in the International Tuberculosis Campaign. The project initially began in Europe in the aftermath of World War II. However, the program extended beyond Europe when UNICEF contributed $2 million to expand the program to other continents.

In 1974 WHO included BCG in the list of recommended vaccines for developing countries. In 1974 fewer than 5% of children worldwide were immunized by age 1 against diphtheria, polio, tuberculosis, pertussis, measles, and tetanus. The Expanded Programme on Immunization would help bring vaccination against these six diseases to many underserved areas.

Still a leading killer worldwide, tuberculosis is less prevalent in the United States than it used to be. According to the CDC, 9,029 new cases of TB were reported in the United States in 2018.

{You can find all the sources I used by clicking here.}

Let's talk infectious diseases, the reason for vaccines: ᴾⁿᵉᵘᵐᵒᶜᵒᶜᶜᵃˡ ᵈⁱˢᵉᵃˢᵉ

Pneumococcal disease is caused by common bacteria (Streptococcus pneumoniae) that can attack different parts of the body.

When these bacteria invade the lungs, they can cause pneumonia; when they invade the bloodstream, they can cause sepsis; and when they invade the covering of the brain, they can cause meningitis. These invasive infections are serious, often require treatment in the hospital, and can lead to death. The bacteria can also cause milder common conditions like middle-ear infection (otitis media) and sinusitis.

Pneumococcal disease is a leading cause of serious illness throughout the world. About 1.3 million persons visit emergency departments in the US each year with pneumonia, which is often caused by pneumococcal infections, and nearly 50,000 people will die from pneumonia. Fewer people will get pneumococcal meningitis or bloodstream infection, but the mortality rate for these infections is higher, even with proper treatment.

There are two main types of pneumococcal disease: non-invasive and invasive. The non-invasive form of the disease is less serious, whereas invasive is fatal in 10% of cases.

Non-invasive pneumococcal disease causes a mild infection where the s. pneumoniae bacteria can spread through the nose, throat, and upper and lower respiratory tracts. The bacteria is associated with a number of conditions: acute bronchitis, sinusitis, and otitis media (inflammation in the middle ear).

Invasive PD is more serious than the non-invasive type and occurs inside the blood or in a major organ. There are several types of invasive pneumococcal disease including pneumonia, meningitis, sepsis, bacteremia, osteomyelitis, and septic arthritis.

Treatment depends on the type of pneumococcal disease. Noninvasive pneumococcal infections may not need treatment. Invasive pneumococcal infections will require antibiotics.

The best prevention of pneumococcal disease is vaccination. While there are numerous strains of s. pneumoniae and vaccination cannot prevent all of them, pneumococcal vaccines can protect you from the most common strains.

In 1881, Louis Pasteur and U.S. Army physician George Miller Sternberg both independently discovered the Streptococcus pneumoniae bacterium that is responsible for cases of pneumonia and meningitis, as well as other illnesses.

The first whole-cell vaccine was tested on 50,000 miners in Africa in 1911. However, the date was inconclusive so the vaccine was abandoned. Another vaccine was introduced in 1945 but coincided with the advent of widespread penicillin use. With penicillin being viewed as an effective treatment for pneumococcal infections, the vaccine did not gain much traction.

One challenge in producing a pneumococcal vaccine involved determining which of the more than 90 types of pneumococcal bacteria produced the most disease. Finally, in 1977 a vaccine was licensed that protected against 14 types of pneumococcal bacteria. In 1983, Merck expanded on this work by producing a vaccine against 23 types of pneumococcal bacteria. This vaccine is still used today in adults 65 and older, as well as for individuals aged two or older who are at high risk for disease.

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