In order to understand how the COVID-19 vaccine allows us to be more resistant to the Coronavirus, we must first understand how the human immune system combats illnesses. In our bloodstream we have white blood cells which fight against infections diseases, yet there are different types of those immune cells which have different roles. Here are some of the most important ones and their roles:
Macrophages are white blood cells that consume and digest germs and dead cells, and they leave behind sections of the invading germs, called “antigens”. The body identifies antigens as dangerous and stimulates antibodies to attack them.
T-lymphocytes are another type of defensive white blood cell. They attack cells in the body that have already been infected. They also are known as the “memory cells” because after they encounter
B-lymphocytes are defensive white blood cells. They produce antibodies that attack the pieces of the virus left behind by the macrophages. When familiar antigens are detected, B-lymphocytes produce antibodies to attack them
In the end, the vaccine’s role is to allow your body to produce “memory” T-lymphocytes as well as B-lymphocytes that will remember how to fight that virus or germ in the future. It is important to understand that the COVID-19 vaccine does NOT cause COVID.
Different Types of Vaccines
There are four main types of vaccines: RNA (nucleic acid), viral vectors, whole virus, and protein subunits
Pfizer and Moderna vaccines are mRNA Vaccines. mRNA Vaccines contain a section of the genetic code found in the virus. these vaccines contain a portion of the genetic material from COVID-19. Our bodies use the mRNA to create a harmless protein that is unique to the virus. Our bodies recognize that the protein is a possible threat and build T-lymphocytes and B-lymphocytes that will remember how to fight the COVID-19 virus if we are infected in the future.
Protein subunit vaccines include harmless pieces (proteins) of the virus that causes COVID-19 instead of the entire germ. Once the vaccine enters our blood stream, our bodies recognizes the proteins as “outsiders” and build T-lymphocytes and antibodies that destroy the proteins. The T-lymphocytes will remain in the bloodstream, and if COVID-19 ever enters our body in the future, we already have the antibodies to deactivate the virus.
Whole virus vaccines use a weakened or inactive version of the virus. The weakened or inactive virus is injected, and then the body creates T-lymphocytes and B-lymphocytes to destroy the virus. If your are later exposed to the virus, your body will already have the antibodies and white blood cells to deactivate and destroy the virus before the infection becomes serious.
Vector vaccines contain a modified version of a virus. Inside the shell of the modified virus, there is material from the virus that causes COVID-19. This is called a “viral vector.” Once the viral vector is inside our cells, the genetic material gives cells instructions to make a protein that is unique to the virus that causes COVID-19. Using these instructions, our cells make copies of the protein. This again leads our bodies to build T-lymphocytes and B-lymphocytes that will remember how to fight that virus if we are infected in the future. The Johnson & Johnson, AstraZeneca, and the University of Oxford have a vector COVID-19 vaccine. The company Novavax is currently working on a vector COVID-19 vaccine.
