Vaccines: Then and Now

This nutrition bite takes a look at what is the mRNA vaccine, how it differs from older vaccines and how an mRNA vaccine works.

Firstly, What IS A Vaccine??

A vaccine is a biological preparation that teaches our body how to defend itself against disease by triggering a preemptive immune response. This immune response is stored within our body’s immune system and then reacts when our body is exposed to the pathogen the vaccine was designed for.

This stored immune response can prevent active infection altogether or allow the body to recover from the disease without having to experience serious illness.

Historically, vaccines were created to give protection from illness caused by viruses, bacteria, venom and other toxins. It’s widely accepted that, thanks to the success of vaccines, diseases such as smallpox were eliminated and once very common and high-risk diseases such as mumps, measles and influenza are now under control. (1)

Types Of Vaccines

Vaccines are most commonly administered through injections into muscle or subcutaneous tissue but can also be administered nasally through a spray or orally. (2)

Here are several commonly used types of vaccines that have long been extensively studied and developed:

Live Attenuated Vaccines introduce a disease in a weakened and asymptomatic state. That is to say, a tiny amount of a pathogen is introduced to the body. Because the pathogen isn’t at full strength, the immune system can safely learn the disease’s antigens (programming, so to speak) and in turn create and store the appropriate antibodies.

Protection from measles, mumps, influenza and rubella use a live attenuated vaccine.
Inactivated Vaccines introduce the dead cells of a virus or bacteria into the body. Even when dead, the body still detects the antigens of the virus and in turn creates and stores the appropriate antibodies. Inactivated vaccines commonly require several doses or booster shots in order for the body to develop full defense against a pathogen.

Protection from Polio, Hepatitis A and Rabies use inactivated vaccines.
Subunit/Conjugate Vaccines inject a protein or carbohydrate specific to a disease without having to inject the entire disease’s components. These isolated proteins or carbohydrates allow the immune system to create antibodies without having the entirety of the disease within the body.

Protection from Hepatitis B, HPV, and Influenza use subunit vaccines.
Toxoid Vaccines introduce to the body toxoids, a negated form of a toxin. Certain forms of bacteria harm the body by releasing toxins. Toxoids introduce the body to a toxin without the harmful effects so that the immune system can learn how to negate the actual toxin in case of exposure.

Protection from Diphtheria and Tetanus use toxoid vaccines. (3,4)

What Is the mRNA Vaccine?

Messenger RNA (mRNA) vaccines work just like any vaccine by giving immunity or protection against serious illness from a disease. However, the process of developing immunity is different because antibodies are created without actual exposure to the disease.

Unlike other vaccines that introduce disease using either live, dead or proteins derived from the actual pathogen, mRNA vaccines use the information in a virus’s genes as a blueprint. In the case of the recently developed vaccines, the blueprint provides our immune system with the map of the proteins on the outer membrane of the virus, which essentially teaches our immune system how to respond to it.

To better understand how mRNA vaccines work, here’s a reminder of how viruses cause infection: When a virus enters our body, it attaches itself to our cells and instructs our cells to create copies of the virus. This is the infection and it remains active until our immune system develops antibodies and can begin to overpower it.

An mRNA vaccine utilizes this process of infection to our immunity’s advantage.

An mRNA vaccine works by injecting only an isolated part of a virus’s RNA that creates its protein spikes. The same way a virus enters our cells to create copies of itself, the mRNA enters our cells and ‘teaches’ them how to create copies of spike proteins of a virus.

Take note that mRNA doesn’t teach our cells to create copies of a virus itself but just its spike proteins. Once these spike proteins are replicated, our immune system has learned how to fight it off and then store the right antibodies in the event of exposure to the actual virus. (5,6)

Vaccine Ingredients

Every vaccine will have its own unique ingredients as part of its formulation, however most vaccines share common components such as preservatives, stabilizers, adjuvants (immune response enhancers), culture materials, residual inactive ingredients and antibiotics. These ingredients each serve a purpose in keeping the vaccine stable, effective and consistent in quality. [7]

The understandable concern with these components however are the ingredients used such as:

Formaldehyde, a known carcinogen, is a common residual active ingredient.
Thimerosal, an ethyl mercury, is used as a preservative, but NOT to be confused with methylmercury.
Antibiotics, which help keep a vaccine from getting contaminated from bacterial growth.

Although controversial, these ingredients have been studied over decades and most authorities deem them safe at the dose included within traditional vaccines.

This is another important factor that makes these new mRNA vaccines different: the ingredients only include lipids, salts and sugars along with the mRNA itself. [7] This is one reason some people who are against traditional vaccines have been more open to these news ones, in light of the pandemic.