COVID-19 VACCINES: WHAT'S IN THEM AND HOW THEY WORK.

The first COVID-19 shot in the United States was administered on December 14, 2020. The first vaccine to be rolled out was from Pfizer-BioNTech. Afterwards, Moderna received FDA approval for its vaccine to be used for emergency use in the country. Meanwhile in the United Kingdom, both the Pfizer and AstraZeneca vaccines are currently being used to inoculate the population. But what's in the vaccines? We hear scientists claiming that how the vaccines are made is due to ground breaking scientific research. We also hear talk about something called mRNA technology, implemented in the making of these new vaccines, which makes them more effective in the fight against this novel coronavirus. But, what is mRNA and how does it work? 

How vaccines are made.

A vaccine is usually made by taking a watered down version of an infection or scientists may use dead cells of a virus. Called the viral vector vaccine, the final product, which includes the virus components is then injected into the recipient, in order to stimulate a response from the individual's immune system.  The immune system, believing it is under attack, creates antibodies to fight against the infection, that way if ever the person were to be exposed to the illness again i.e. the real infection/virus, the body will be able to recognise it and immediately launch the appropriate immune response to attack and kill the invading cells.

Examples of Viral Vector Vaccine.

Examples of this are the vaccines made by Sinopharm and AstraZeneca. One of the five Chinese pharmaceutical companies, Sinopharm, is a contender in the race to create an affordable drug that can be distributed worldwide. Sinopharm grew COVID-19 cells in their lab, then killed them before incorporating these cells into their vaccine. 

AstraZeneca is one of the vaccines that is now available to poorer countries as part of the COVAX. 170 million doses had already been promised for distribution through this facility. The company created their 'viral vector vaccine', using a weakened version of a common cold virus that was genetically altered, making it unable to reproduce in humans.

However, not all vaccines are the same. Pfizer and Moderna made theirs differently. They used a process called mRNA.

What is mRNA?

mRNA is messenger ribonucleic acid. The principal role of RNA is to act as a messenger, carrying instructions from DNA for the synthesis of proteins, although in some viruses RNA rather than DNA carries the genetic information. The COVID-19 virus is one such variant.

Scientists therefore have used mRNA technology they made, to carry instructions to the immune system for making anti-COVID-19 cells. The vaccines are the first of their kind and are touted as the "vaccine of the century".

It should be noted that the idea of mRNA has been studied for decades, but wasn’t fully realized to help develop new therapies and vaccines until 2010 (same year Moderna was founded). While most vaccines use weak, harmless or inactivated versions or components of a virus (as fully explained above) to create antibodies, mRNA does not.

How the Pfizer and Moderna vaccines work

The Pfizer and Moderna vaccines include a molecule that contains the mRNA. When it is injected into your body, the mRNA sends a message instructing your cells to produce what is called a 'spike protein' that is similar to the one made by the SARS-CoV-2 virus (COVID-19). If afterwards you were to be exposed to the COVID-19 virus, or become ill because of it, your body will recognize this protein as a foreign entity and then build an immune response to kill it — antibodies that have actual memory to combat the illness.

In recent trials the mRNA vaccine showed a greater than 94-percent efficacy in preventing infections with minimal side effects during rigorous clinical trials.

Former Centers for Disease Control and Prevention Director, Tom Frieden recently tweeted perhaps the simplified explanation of how mRNA works, stating "Think of it as an email sent to your immune system that shows what the virus looks like, instructions to kill it, and then — like a Snapchat message — it disappears."

Overall, mRNA is seen as a game-changer. Using the mRNA technology allows for much shorter manufacturing times and the process can be standardized and scaled up, allowing faster development than traditional methods.

Is it safe?

Scientists claim both Pfizer's and Moderna’s vaccines are safe, showing minimal side effects during clinical trials, and only three people who have taken the Pfizer vaccine so far in the world have reportedly endured “severe” side effects, two of which had similar reactions to other vaccinations.

To achieve emergency use approval from the FDA, the mRNA vaccines experienced the same rigorous safety assessment as all other vaccines. It’s approved only when the expected benefit outweighs any potential risks, which has now happened for both.

Building immunity

Pfizer and Moderna’s vaccines require two doses, which isn’t uncommon for vaccines. For comparison, MMR (2), DTaP (3), polio (4), hepatitis B (3), pneumococcal (3) and varicella (2) all require two doses or more.

Pfizer’s requires a second injection 21 days after the first, at which point you are expected to have 95-percent protection against COVID-19.

Moderna’s vaccine requires a second shot 28 days after the first, when you will have 94-percent. 

Is there anyone who should not take it?

Almost everyone should be able to get the vaccine, even the frailest elderly people. Only one group was called out by the FDA as those who should avoid the vaccine — people who have a known history of a severe allergic reaction to any component of the Pfizer/BioNTech vaccine.

If you are pregnant, consult your doctor if you are considering getting vaccinated.

Other vaccines

Earlier this year (2021), the Johnson & Johnson was approved for emergency use in the United States and has gotten the okay from the WHO.  This vaccine is made out of the adenovirus, which provides genetic material that encodes COVID-19 genes into your cells to make the proteins to fight them. Johnson & Johnson took a similar approach in developing its Ebola vaccine. The vaccine is a single shot and doesn’t require storage at sub-zero temperatures like Pfizer's shot.

More vaccines to come

Currently there are 114 candidate vaccines. About 33 candidate vaccines are in stage 3 clinical trials and so far 14 vaccines have been authorized for use across several countries.

Edited May 8, 2021.