Let's talk vaccines: ⱽᵃᶜᶜⁱⁿᵉ ᵀʸᵖᵉˢ

There are several different types of vaccines. Each type is designed to teach your immune system how to fight off certain kinds of germs—and the serious diseases they cause.

When scientists create vaccines, they consider:

▪️How your immune system responds to the germ

▪️Who needs to be vaccinated against the germ

▪️The best technology or approach to create the vaccine

Vaccines are generally classified as live or non-live (sometimes loosely referred to as ‘inactivated’) to distinguish those vaccines that contain attenuated replicating strains of the relevant pathogenic organism from those that contain only components of a pathogen or killed whole organisms. In addition to the ‘traditional’ live and non-live vaccines, several other platforms have been developed over the past few decades.

There are several types of vaccines, including:

▪️Inactivated vaccines

▪️Live-attenuated vaccines

▪️Messenger RNA (mRNA) vaccines

▪️Subunit, recombinant, polysaccharide, and conjugate vaccines

▪️Toxoid vaccines

▪️Viral vector vaccines

𝙸𝚗𝚊𝚌𝚝𝚒𝚟𝚊𝚝𝚎𝚍 𝚟𝚊𝚌𝚌𝚒𝚗𝚎𝚜 (𝙺𝚒𝚕𝚕𝚎𝚍 𝙰𝚗𝚝𝚒𝚐𝚎𝚗)

Inactivated vaccines use the killed version of the germ that causes a disease. They are made by making a pathogen safe for use in a vaccine by treatment with heat or chemicals. This kills the pathogen, making it incapable of replication, but still allows it to induce an immune response to at least some of the antigens contained within the organism.

Inactivated vaccines usually don’t provide immunity that’s as strong as live vaccines. So you may need several doses over time (booster shots) in order to get ongoing immunity against diseases.

Inactivated vaccines are used to protect against:

▪️Hepatitis A

▪️Flu (shot only)

▪️Polio (shot only)

▪️Rabies

𝙻𝚒𝚟𝚎-𝚊𝚝𝚝𝚎𝚗𝚞𝚊𝚝𝚎𝚍 𝚟𝚊𝚌𝚌𝚒𝚗𝚎𝚜

Live vaccines use an attenuated form of the germ that causes a disease. (Attenuated means having been reduced in force, effect, or value.) In some cases, microorganisms can be attenuated or disabled so that they lose their ability to cause significant disease (pathogenicity) but retain their capacity for transient growth within an inoculated host. Attenuation can often be achieved by growing a pathogenic bacterium or virus for prolonged periods under abnormal culture conditions.

Because these vaccines are so similar to the natural infection that they help prevent, they create a strong and long-lasting immune response. Just 1 or 2 doses of most live vaccines can give you a lifetime of protection against a germ and the disease it causes.

Live vaccines are used to protect against:

▪️Measles, mumps, rubella (MMR combined vaccine)

▪️Rotavirus

▪️Smallpox

▪️Chickenpox

▪️Yellow fever

▪️Influenza (nasal spray)

▪️Shingles

𝚂𝚞𝚋𝚞𝚗𝚒𝚝, 𝚛𝚎𝚌𝚘𝚖𝚋𝚒𝚗𝚊𝚗𝚝, 𝚙𝚘𝚕𝚢𝚜𝚊𝚌𝚌𝚑𝚊𝚛𝚒𝚍𝚎, 𝚊𝚗𝚍 𝚌𝚘𝚗𝚓𝚞𝚐𝚊𝚝𝚎 𝚟𝚊𝚌𝚌𝚒𝚗𝚎𝚜

Subunit, recombinant, polysaccharide, and conjugate vaccines use specific pieces of the germ—like its protein, sugar, or capsid (a casing around the germ).

Because these vaccines use only specific pieces of the germ, they give a very strong immune response that’s targeted to key parts of the germ. They can also be used on almost everyone who needs them, including people with weakened immune systems and long-term health problems.

One limitation of these vaccines is that you may need booster shots to get ongoing protection against diseases.

These vaccines are used to protect against:

▪️Hib (Haemophilus influenzae type b) disease

▪️Hepatitis B

▪️HPV (Human papillomavirus)

▪️Whooping cough (part of the DTaP combined vaccine)

▪️Pneumococcal disease

▪️Meningococcal disease

▪️Shingles

▪️Influenza (injection)

𝚃𝚘𝚡𝚘𝚒𝚍 𝚟𝚊𝚌𝚌𝚒𝚗𝚎𝚜

Toxoid vaccines use a toxin (harmful product) made by the germ that causes a disease. They create immunity to the parts of the germ that cause a disease instead of the germ itself. That means the immune response is targeted to the toxin instead of the whole germ.

Like some other types of vaccines, you may need booster shots to get ongoing protection against diseases.

Toxoid vaccines are used to protect against:

▪️Diphtheria

▪️Tetanus

𝚅𝚒𝚛𝚊𝚕 𝚟𝚎𝚌𝚝𝚘𝚛 𝚟𝚊𝚌𝚌𝚒𝚗𝚎𝚜

For decades, scientists studied viral vector vaccines. Some vaccines recently used for Ebola outbreaks have used viral vector technology, and a number of studies have focused on viral vector vaccines against other infectious diseases such as Zika, flu, and HIV. Scientists used this technology to make COVID-19 vaccines as well.

Viral vector vaccines use a modified version of a different virus as a vector to deliver protection. Several different viruses have been used as vectors, including influenza, vesicular stomatitis virus (VSV), measles virus, and adenovirus, which causes the common cold. Adenovirus is one of the viral vectors used in some COVID-19 vaccines being studied in clinical trials.

Viral vector vaccines are used to protect against:

▪️COVID-19

𝙼𝚎𝚜𝚜𝚎𝚗𝚐𝚎𝚛 𝚁𝙽𝙰 (𝚖𝚁𝙽𝙰) 𝚟𝚊𝚌𝚌𝚒𝚗𝚎𝚜

mRNA vaccines are a new type of vaccine to protect against infectious diseases. To trigger an immune response, many vaccines put a weakened or inactivated germ into our bodies. Not mRNA vaccines. Instead, they teach our cells how to make a protein—or even just a piece of a protein—that triggers an immune response inside our bodies. That immune response, which produces antibodies, is what protects us from getting infected if the real virus enters our bodies.

COVID-19 mRNA vaccines give instructions for our cells to make a harmless piece of what is called the “spike protein.” The spike protein is found on the surface of the virus that causes COVID-19.

Once the instructions (mRNA) are inside the muscle cells, the cells use them to make the protein piece. After the protein piece is made, the cell breaks down the instructions and gets rid of them.

Next, the cell displays the protein piece on its surface. Our immune systems recognize that the protein doesn’t belong there and begin building an immune response and making antibodies, like what happens in natural infection against COVID-19.

At the end of the process, our bodies have learned how to protect against future infection. The benefit of mRNA vaccines, like all vaccines, is those vaccinated gain this protection without ever having to risk the serious consequences of getting sick with COVID-19.

mRNA vaccines do not use the live virus that causes COVID-19.

They do not affect or interact with our DNA in any way. mRNA never enters the nucleus of the cell, which is where our DNA is kept.

The cell breaks down and gets rid of the mRNA soon after it is finished using the instructions.

Future mRNA vaccine technology may allow for one vaccine to provide protection for multiple diseases, thus decreasing the number of shots needed for protection against common vaccine-preventable diseases.

Beyond vaccines, cancer research has used mRNA to trigger the immune system to target specific cancer cells.

Scientists predict that mRNA is going to transform vaccines in the future and it already has with COVID. It's one of the reasons the vaccine was created so fast.

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