Covid-19 vaccine 101

Covid-19 vaccine 101

By Dr. Ava Mainieri
Head of Research, She/her

By Dr. Kathleen Jordan, MD
Senior VP of Medical Affairs, She/her

3 min read

Today, December 10, 2020, the U.S. Food and Drug Administration will meet to discuss the request for emergency use authorization of the Covid-19 vaccine from Pfizer.

With so much information and misinformation about Covid-19 vaccines, we, at Tia, want to help our community understand to help you understand *wtf* is really going on. We’re doing exactly that with regular drops of THE DOSE, your science-backed guide to all things Covid-19 vaccines.

THE DOSE is brought to you by geneticist and evolutionary biologist, Dr. Ava Mainieri, Head of Research at Tia, and infectious disease expert, Dr. Kathleen Jordan, Senior VP of Medical Affairs at Tia.

How does the Covid-19 vaccine work?

The first Covid-19 vaccines are mRNA vaccines which act as a set of instructions injected into our cells. Our cell machinery uses the instructions to develop a protein that looks *very similar* to the spike protein on the surface of the Covid-19 virus. Our immune response develops antibodies against that protein and the injected mRNA degrades rapidly.

Let’s start at the beginning (aka the infection)

When germs (bacteria or viruses) invade the body, they attack and multiply. The immune system fights infections with white cells.It can take several days for the body to make and use all these germ-fighting tools (especially if this is the first encounter). After infection, the body keeps a few T-lymphocytes, memory cells, so, if it encounters the same germ again it can jump into action quickly!

So, what exactly is a vaccine?

Most vaccines are substances that simulate an infection with a weakened or dead version of the germs that cause the disease they are protecting against, without presenting the danger of infection. The immune system response causes the production of antibodies and T-lymphocytes which will protect against an actual infection.

And what’s an mRNA vaccine?

Messenger RNA or mRNA vaccines work like an instruction manual, introducing mRNA sequences to encode disease-specific Messenger RNA or mRNA vaccines work like an instruction manual, introducing mRNA sequences to encode disease-specific antigens* to trigger an immune response

Antigens are foreign substances that induce immune responses to produce antibodies.

antigens to trigger an immune response.


mRNA never enters the nucleus of the cell (where the DNA is). The cell breaks down and disposes of the mRNA after carrying out the instructions. It does not affect our genetic code.

While it’s true that there are currently no licensed mRNA vaccines in the U.S., researchers have been working with them for decades. mRNA vaccines have been studied for the flu, Zika, rabies, and cancer research.

These vaccines have been made in
record time due to collaboration, funding, and the help of research participants.No steps in the normal vaccine development have been skipped or compromised.

THE DOSE is your science-backed guide to Covid-19 vaccines, from Tia. In service of science-backed public health, share THE DOSE with a friend!