Showing posts with label measles. Show all posts
Showing posts with label measles. Show all posts

Monday, September 20, 2021

Let's talk infectious diseases, the reason for vaccines: ᶜᵒᵐᵇⁱⁿᵃᵗⁱᵒⁿ ⱽᵃᶜᶜⁱⁿᵉ: ᴹᴹᴿ

In 1971 the measles, mumps, and rubella (MMR) combination vaccine was licensed for use. Combination vaccines have several advantages over single vaccines. They reduce the need for several separate injections, and they reduce the costs of stocking and shipping multiple containers. Combination vaccines can help improve overall vaccination rates by simplifying the vaccination process.

One dose of MMR vaccine is 93% effective against measles, 78% effective against mumps, and 97% effective against rubella.

Two doses of MMR vaccine are 97% effective against measles and 88% effective against mumps.


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

Let's talk infectious diseases, the reason for vaccines: ᴬʳᵉ ᵐᵉᵃˢˡᵉˢ ᵃⁿᵈ ʳᵘᵇᵉˡˡᵃ ᵗʰᵉ ˢᵃᵐᵉ?

𝘼𝙧𝙚 𝙢𝙚𝙖𝙨𝙡𝙚𝙨 𝙖𝙣𝙙 𝙧𝙪𝙗𝙚𝙡𝙡𝙖 𝙩𝙝𝙚 𝙨𝙖𝙢𝙚?

Short answer: No.

Longer answer: It would be easy to think that measles and rubella, also called German Measles, are the same disease. It would be easy to think that because of the name German Measles assigned to the disease rubella. And because measles is also known as rubeola. Really, how much more confusing can it get? 🤷‍♀️


While they do have some similarities, they have some pretty big differences.

Let's outline the similarities first:

▪️ Both diseases are caused by an RNA virus.

▪️ They have similar symptoms and are spread by respiratory droplets.

▪️ Rashes are a distinct marker of each disease.

And now the differences:

▪️ Even though both are caused by RNA viruses, it is two different families. Measles belongs to the Paramyxoviridae family and Rubella belongs to the Matonaviridae family.

▪️ German measles are mild while measles cannot, and should not, be considered mild. German measles are not life-threatening while measles are.

▪️ Both the appearance and the length of the rashes differ.

▪️ Symptoms for measles lasts twice as long as rubella.

▪️ The virus that causes measles specifically invades the respiratory system while the virus that causes rubella invades lymph nodes, eyes, and skin.

▪️ Symptoms for measles are more severe and numerous.


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

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


Measles is caused by an extremely contagious virus called paramyxovirus that replicates in your throat and nose. It's spread through respiratory droplets when an infected individual sneezes, coughs, or even talks. The virus can live in the air and on surfaces for up to two hours after a person with measles symptoms has left the area. It invades your respiratory system, causing fever and flu-like symptoms, and then spreads throughout your body. As your antibodies attack the virus, damage to the walls of tiny blood vessels occurs, leading to the measles rash.

An infected person is contagious for around eight days—four days before through four days after the measles rash appears. Measles is so contagious that one infected person who is exposed to 10 people who aren't immune to measles will infect 9 of the 10.


About 7 to 14 days after exposure to someone with measles, people without immunity to measles can develop measles symptoms, some of which are similar to the flu, including:

▪️Fever

▪️Dry cough

▪️Runny nose, sneezing, and congestion

▪️Red, watery eyes from conjunctivitis

▪️Sensitivity to light

▪️Poor appetite

▪️Swollen glands

▪️Koplik spots, small, bright red spots with a bluish-white central dot that are often found inside the mouth, on the inside of cheeks, and on the soft palate.

The classic measles rash is 3-5 days after the other symptoms appear. Unlike many other viral rashes, such as roseola and chickenpox, which typically start on the trunk, the measles rash starts on the face and head. Other things to watch for regarding the measles rash:

▪️This red, blotchy rash will spread down your or your child's body over the next three days, eventually reaching your hands and feet after starting around your hairline.

▪️It usually lasts about five to six days.

▪️After three to four days, the rash may no longer turn white when you push on it.

▪️Areas, where the measles rash was most severe, may start to peel.

▪️Once the rash begins to go away, it will fade in the same order that it started.

Measles is a serious, HIGHLY infectious disease that causes serious complications.

Although some people continue to claim that measles is a mild infection, it can have severe complications. In fact, one or more complications occur in around 30% of cases.

People who are at the highest risk for developing complications include: children under age 5, adults over age 20, pregnant women, and people with compromised immune systems.


Common complications include:

▪️Ear infections

▪️Diarrhea

More severe complications from measles include:

▪️Pneumonia: This lung infection is the main cause of measles death in children. Approximately 1 in 20 kids with measles develop pneumonia.

▪️Encephalitis: This is an inflammation of the brain that occurs in about 1 in 1,000 people. It involves more severe symptoms, such as fever, headache, vomiting, stiff neck, meningeal irritation, drowsiness, convulsions, and coma. This complication of measles usually begins about six days after the start of the measles rash and can lead to death, deafness, or permanent brain damage.

▪️Pregnancy issues: Measles can lead to preterm labor, low birth weight, and even pregnancy loss.

▪️Subacute sclerosing panencephalitis (SSPE): This is a deadly, but rare complication caused by defective measles virus. About seven to 10 years after having measles, children and young adults with SSPE develop progressive neurological symptoms, including memory loss, behavior changes, uncontrollable movements, and even seizures. As symptoms progress, they may become blind, develop stiff muscles, become unable to walk, and eventually deteriorate to a persistent vegetative state. Children who had measles before age 2 seem to be more at risk of developing this complication. People with SSPE usually die within one to three years of first developing symptoms. Fortunately, as the number of measles cases has been dropping in the post-vaccine era, so have the number of SSPE deaths.

▪️Seizures: In 0.6 percent to 0.7 percent of people, seizures with or without fever can occur as a complication of measles.

▪️Death: In the United States, measles is fatal in about 0.2 percent of cases.


Measles has a devastating impact on the body's immune system that could make it harder to fight infections for years.

The virus can cause "immune amnesia" - meaning the body forgets how to fight bugs it once knew how to beat.

Measles also resets the immune system to a "baby-like" state, compromising its ability to devise ways of tackling new infections.

"Measles is like the first 10 years of an untreated HIV infection compressed into a few weeks - that's the kind of immunological memory damage," said Dr. Michael Mina.

This is a serious problem because the measles are making a comeback due to a decrease in vaccinations.

Measles appeared in print as early as 0910 when a Persian physician published an account of measles and smallpox being two distinct and unique diseases.

In 1757, Scottish physician Francis Home transmitted measles from infected patients to healthy individuals via blood, demonstrating that the disease was caused by an infectious agent.

The Faroe Islands was experiencing a measles epidemic in 1846 so Danish physician Peter Panum traveled there and spent 5 months studying the disease. His observations were that measles was not just a childhood disease but affected people of all ages, the isolation of the Faroe Islands served to protect them from illness but also when illness hit the islands the mortality rate was high, the measles rash appeared 14 days after a person was exposed to the disease, and surviving the infection resulted in lifelong immunity against the disease.

Figuring out a cure for measles was proving to be difficult and very slow-going. Finally in 1916 French researchers Charles Nicolle, MD, and Ernest Conseil, MD showed that measles patients have specific protective antibodies in their blood. The researchers then demonstrated that serum from measles patients could be used to protect against the disease.

But it wasn't until 1954 that the measles virus was finally isolated and captured by Thomas Peebles, MD. The successful isolation of the virus was used to create a series of vaccines. In 1958 the first vaccine was tested on 11 children. All 11 vaccinated children developed measles antibodies, but nine also developed a mild rash—the vaccine didn’t cause full-blown measles, but it did cause symptoms. The researchers realized the virus used for the vaccine had to be weakened even more.

By 1960 there still wasn't a vaccine researchers felt good about mass producing. However, when an outbreak happened in February of 1960 and the 23 children who had been vaccinated with the most recent effort were exposed, they didn't fall ill. The vaccine still caused too many side effects but since it did its job and protected the children from the disease vaccine production went forward.

Successfully demonstrating its safety and efficacy, first in monkeys and then humans, John Enders and colleagues declared their measles vaccine capable of preventing infection in 1963.

Their Edmonston-B strain of measles virus was transformed into a vaccine licensed in the United States in 1963, and nearly 19 million doses would be administered over the next 12 years. In 1968 this vaccine was weakened (attenuated) enough to administer it without human blood proteins to lessen the side effects. Called the Moraten strain (More Attenuated Enders), it has been the only measles vaccine used in the United States since licensure.

In 1971 the MMR was licensed for use. It is a combination measles, mumps, and rubella vaccine. That combination will be discussed in a different post.

In 1978, the CDC declared a goal of eliminating measles from the United States by 1982. Although this goal would not be met, widespread vaccination drastically reduced the incidence of the disease, and it would be declared eliminated in the country by 2000. That was reversed in 2011 when the United States had 220 reported cases and since then the measles continue to have pockets of outbreaks every year. In 2020 the United States had 13 reported cases, in 2019 it was 31 cases which was the highest since 1992. That there continue to be outbreaks is concerning.


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

Monday, September 13, 2021

Let's talk vaccines: ᵀʰᵉ ᴴⁱˢᵗᵒʳʸ ᵒᶠ ⱽᵃᶜᶜⁱⁿᵉˢ

Buckle up, we are taking a road trip to discover vaccines. 

A great place to start talking about vaccines is at the beginning. And chances are good the beginning is not where any of us think it is.

Throughout history, there have been many illnesses and diseases. But two have caused perhaps the most deaths and illnesses throughout the whole of time. Measles and Smallpox. Thought to be the "same" thing, in 0910 a Persian physician was the first to publish a written account titled “On Smallpox and Measles” in which he describes the two diseases as being distinct and unique from each other. Which meant that two different ways of treating them would be needed, based on their specific characteristics.

But the story of vaccines does not begin with the first vaccine in 1798 - Edward Jenner’s use of material from cowpox pustules to provide protection against smallpox. Rather, it begins with the long history of infectious disease in humans, and in particular, with early uses of smallpox material to provide immunity to that disease.

Evidence exists that the Chinese employed smallpox inoculation (or variolation, as such use of smallpox material was called) as early as 1000 CE. In the late 1600s Emperor K'ang Hsi, who had survived smallpox as a child, had his children inoculated.

There were two methods of inoculation known to be used in those days. Grinding up smallpox scabs and blowing the matter into the nostril or scratching matter from a smallpox sore into the skin.

As infectious diseases swept through nations the need for a way to halt these diseases and treat them was being pursued. The Chinese method of inoculation hadn't caught on and/or people were suspicious of its ability to stop the disease. Smallpox and measles were joined by epidemics of pertussis (whooping cough), typhoid fever, diphtheria, yellow fever, scarlet fever, cholera, and polio...to name a few.

According to historical records, between 1545 and 1817 various parts of the world experienced smallpox, whooping cough, measles, typhoid fever, diphtheria, and yellow fever epidemics.

An epidemic is a disease that affects a large number of people within a community, population, or region. A pandemic is an epidemic that's spread over multiple countries or continents.

Presumably, due to an increase in travel and transportation advancements, pandemics became the concern starting with a cholera outbreak in 1817 that swept through India, Asia, and then traveled throughout the world leading to seven major cholera pandemics, each lasting several years, between 1817 and present day. Yes! Present-day!

Prior to the gaining popularity of early inoculation methods, the treatment for these diseases consisted of quarantining, providing comfort measures, attempting to bring down high fevers, bloodletting, inducement of vomiting, alcohol-laced with herbs, and praying that the person wouldn't die or suffer from physical damage due to the disease.

Once again, the Chinese made vaccine headlines (figuratively of course) when Emperor K’ang verbalized support for inoculation in a letter to his descendants in 1661. Having survived a case of smallpox before he became Emperor he wrote:

“The method of inoculation having been brought to light during my reign, I had it used upon you, my sons and daughters, and my descendants, and you all passed through the smallpox in the happiest possible manner…. In the beginning, when I had it tested on one or two people, some old women taxed me with extravagance and spoke very strongly against inoculation. The courage which I summoned up to insist on its practice has saved the lives and health of millions of men. This is an extremely important thing, of which I am very proud.”

In the 1700s variolation started to be practiced more and more as word spread that it worked. Fewer people were dying and that was looked upon favorably.

But what's variolation? Isn't it vaccination? Aren't they the same?

 

Variolation (inoculation) served as a natural precursor to the discovery of vaccination. The development, adoption, and improvement of infectious disease responses are messy processes – there's never a single “eureka” event. There always has to be a precursor, or two, before arriving at the end result.

This method of treatment was used strictly with smallpox outbreaks as the disease provided a visible form of the infection to use.

With variolation, a small amount of the pus from a person infected with smallpox was placed into the skin of an uninfected person. The thought was that the disease would then take hold in the previously uninfected person but in a mild form. It was discovered to be less dangerous to contract it through inoculation than to contract it naturally.

This method of safeguarding against dangerous diseases was never risk-free, nor did advocates of the method claim it to be risk-free. But it greatly reduced the mortality rates. Between 1% to 2% of those variolated died as compared to 30% who died when they contracted the disease naturally.

Inoculation gained popularity in the 1700s.

In 1721 Cotton Mather, thanks to the information his African slave provided him, suggested physician Zabdiel Boylston try the inoculation method as an outbreak of smallpox was ravaging Boston. 248 people were variolated and of those 248, 3% - or 6 people - died. Of those left to the disease and vulnerable to its symptoms 14% died. Thus, variolation had come to the Americas.

Meanwhile, across the pond, Lady Mary Wortley Montagu had been introduced to "engrafting" in Turkey and when arriving back in England in 1721 requested it be done to her two-year-old daughter. Her son had been engrafted while they were in Turkey. Thus, variolation had come to England.

Both Mather and Lady Montagu would come under considerable criticism for advocating variolation, a practice that slowly began to spread as its ability to protect against smallpox became apparent even in light of its fatality rates and the discovery that variolated individuals could pass the disease on to others.

In the 1770s rumors began circulating about a disease called cowpox. People who regularly worked with cattle were claiming that their exposure, and subsequent infection, to cowpox inoculated them against smallpox.

Cowpox is an uncommon illness in cattle, usually mild, that can be spread from a cow to humans via sores on the cow. During an infection, dairy workers may have pustules on their hands. Sufferers can spread the infection to other parts of the body.

Around 1774 farmer Benjamin Jesty inoculated his wife and two sons with matter from a cowpox lesion on one of his cows.

Jesty, having already contracted cowpox, believed himself protected from smallpox infection. When a serious smallpox epidemic hit his Dorset village, he, from his “great strength of mind,” took it upon himself to protect his family. His wife and children survived, and the boys, when challenged with smallpox inoculation in 1789, showed no symptoms.

Mr. Jesty, however, had no interest in systematically testing his methods or publishing his results, and so his finding was largely forgotten. Upon his death, his wife had his tombstone inscribed, “the first person (known) who introduced the cow-pox inoculation.”

Twenty-two years after Benjamin Jesty successfully inoculated his family with cowpox to avoid smallpox, Dr. Edward Jenner began testing and creating what would become the world's first vaccine.

In the 1770s Jenner had also heard the rumors about using cowpox to inoculate against smallpox but he was still in the thick of his medical school studies and residency program.

However, in May 1796 Dr. Jenner inoculated eight-year-old James Phipps with matter from a cowpox sore on the hand of a milkmaid. Phipps suffered a local reaction and felt poorly for several days but made a full recovery. So in July 1796, Jenner inoculated Phipps with matter taken from a fresh human smallpox sore, as if he were variolating the boy, in an attempt to challenge the protection from cowpox. Phipps remained healthy.

Jenner next demonstrated that cowpox matter transferred in a human chain, from one person to the next, provided protection from smallpox.

For the next couple of years, Dr. Jenner continued to test his idea on patients and saw great success. He wrote a paper for the Royal Society of his findings but they rejected it. So Jenner self-published a pamphlet called “An Inquiry into the Causes and Effects of the Variolae Vaccinae, a Disease discovered in some of the Western Counties of England, particularly Gloucestershire, and known by the name of the Cow Pox.” It outlined Jenner’s success in protecting James Phipps from smallpox infection with material from a cowpox pustule, in addition to 22 related cases. At first, the news was received quietly if received at all. But that changed when an associate of Jenner's, Henry Cline, used dried vaccine material provided by Jenner to demonstrate once again that vaccination with cowpox material prevented future smallpox infection.

The vaccine started to gain traction and quickly became preferred over variolation for its improved success and safety.

But, didn't Jenner engraft James Phipps? He took the pus from the infection and placed it under the skin of an uninfected person. That's what people had been doing for years by 1796! So how was what Jenner did different than what everyone else was doing?

So, how are variolation and vaccination different from one another?

Both are using infected pus to infect, in the hopes of immunity, uninfected people.

The difference is subtle but very important. Variolation used viral matter from smallpox patients, usually pus from a light case of smallpox. Jenner's vaccination, meanwhile, used matter from the milder cowpox virus. As a milder disease carrying the same immunities, cowpox matter was much safer. Both methods are also called inoculation because inoculation is the process of introducing a small amount of viral matter into the body in order to teach the body’s immune system to fight off the virus, thus making the patient immune to future infection.

So step one in what would become today's modern vaccination was successfully tested and completed. As is the case with any invention, the first workable treatment would be replaced with an improved option and that cycle would continue until we arrived at the year 2020 and the need for a new vaccine presented itself.

But, that part of the story is much later.

Between Jenner's successful test run of the smallpox vaccine in 1796 and 1879, the vaccine creation and delivery methods stayed the same. In order to meet the demand vaccine farms were created, voices of government endorsed the method, variolation was outlawed in certain parts of the world, and other infectious diseases were being dissected in hopes of developing vaccines.

In the last decade of Jenner's life smallpox mortality rates in Britain declined by approximately 43% thanks to the vaccine.

So what happened in 1879 to push the vaccine forward yet again toward what we know it as today?

What happened was Louis Pasteur was born in 1822.

Between his birth in 1822 and 1879, Pasteur grew up and became an accomplished academic. In 1831 he witnessed firsthand a rabies outbreak and that gave him the desire to solve that problem as well as others. Between 1840 and 1847 Pasteur earned at least 4 degrees. He was found in 1849 teaching Chemistry. In 1854 Pasteur began studying fermentation which would end up being crucial to the next step in modernizing vaccines. Despite a stroke that left his left arm and leg permanently paralyzed, Pasteur persevered in his research and produced the first laboratory-developed vaccine in 1879. It was a vaccine for chicken cholera (Pasteurella multocida).

A happy accident led to this step in vaccine production as Pasteur's assistant didn't follow instructions and the bacteria was exposed to oxygen. Turned out that the oxygen exposed bacteria weakened the disease enough to make it effective in providing protection against the full-strength bacteria.

When Louis Pasteur died in 1895 his life's work had accomplished advancements in vaccine production; he had proved that germs cause disease; he developed vaccines for anthrax and rabies, and he created the process of pasteurization.


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