How do the FDA-authorized vaccines work? ↓

The Moderna and Pfizer FDA-authorized vaccines use mRNA technology to boost your body’s immune response.

While COVID-19 may seem new to many of us, researchers have been studying coronaviruses for over 50 years. During this time, they’ve also been learning how mRNA technology can help develop effective vaccines. mRNA can be thought of as a set of instructions that tell your body’s cells how to make proteins.

  • The mRNA vaccine tells your body to make a small, non-infective portion of the outer part of the COVID-19 virus particle called a “spike protein”.
  • This trains your immune system to recognize the virus and your body responds by building antibodies.
  • Later, if you are exposed to the real virus, these antibodies are then able to attack it and prevent you from getting sick. The antibodies’ ability to prevent sickness is what is meant when people say a vaccine provides immunity.

A key benefit of mRNA vaccines is that the process to develop them can be standardized and scaled up more efficiently than other methods, which has been especially important in our response to COVID-19.

The Johnson & Johnson vaccine is a viral vector vaccine. Viral vector vaccines use a modified version of a different virus (the vector) to deliver important instructions to our cells. For COVID-19 viral vector vaccines, the vector (not the virus that causes COVID-19, but a different, harmless virus) will enter a cell in our body and then use the cell’s machinery to produce a harmless piece of the virus that causes COVID-19. This piece is known as a spike protein and it is only found on the surface of the virus that causes COVID-19.

The cell displays the spike protein on its surface, and our immune system recognizes it doesn’t belong there. This triggers our immune system to begin producing antibodies and activating other immune cells to fight off what it thinks is an infection.

At the end of the process, our bodies have learned how to protect us against future infection with the virus that causes COVID-19. The benefit is that we get this protection from a vaccine, without ever having to risk the serious consequences of getting sick with COVID-19. Any temporary discomfort experienced after getting the vaccine is a natural part of the process and an indication that the vaccine is working.

There are two other vaccines that are currently in their Phase 3 large-scale clinical trials.

As of 4/23/21, the pause on the Johnson & Johnson/Janssen COVID-19 vaccine has been lifted.