How Does Your Body Actually Prevent or Manage Infection?

As yet another variant sweeps across the United States, people are searching for answers. How do I protect myself and others? Can I see family during the holiday? Are we reverting to the restrictions of March 2020?

There might be a lot of unknowns, but thanks to biology and infectious disease research, we do know vaccines are effective at preventing severe illness. T-cells, which the body produces naturally, are a key part of the immune response.

There are two major components of immunity: B-cells and T-cells. B-cells are the body’s first line of defense against infection. They produce antibodies that bind to infection and prevent the body from getting sick.

Vaccines as well as prior COVID-19 infections produce antibodies to prevent against future infection, but variants or mutations of a virus make it harder for the B-cells to recognize infection and therefore give the virus an opportunity to break through. This is why a vaccine or previous COVID-19 infection cannot fully protect against a future COVID-19 infection.

But this is where T-cells come in.

T-cells (specifically CD8 T-cells) are designed to seek out infected cells and kill them. When the T-cells are introduced to a new virus, it can take some time for them to recognize cells as infected, attack and kill them, causing the body to be very sick for a long a time. But because they read infected cells differently than B-cells do, a vaccine, booster, or prior infection, would make it very difficult for a virus to mutate enough to be unrecognizable to the T-cell. Therefore, if you are vaccinated and boosted but still contract the COVID-19 virus, T-cells kick in to shorten infection, lessen the severity of infection, and minimize how infectious you are to others.

Picture a fruit basket with 10 pieces of fruit and one is obviously rotten. A B-cell’s job is to identify rotten fruit. It picks out that one piece of fruit and removes it. It doesn’t recognize the second piece that’s about to turn because it’s not rotten yet. The T-cell, on the other hand, would throw the entire basket away. It doesn’t care which piece is going. It identifies the whole basket as rotten.

As variants emerge, and individuals become increasingly concerned about the efficacy, and in some cases even the necessity, of vaccines, it’s important to remember that while mutations can fool B-cells fairly easily, the T-cells are much harder to trick.

Researchers at Johns Hopkins School of Medicine, Johns Hopkins Bloomberg School of Public Health and the National Institute of Allergy and Infectious Disease teamed up on a recent study to be entered into peer review that investigated the Omicron variant. After looking at 52 epitopes (the part of an antigen molecule to which an antibody attaches itself), found 51 had no mutations. This means T-cells would recognize 98% of the virus as infectious. Researchers can say with a high level of confidence that the T-cells will still be effective at attacking and killing cells infected with Omicron, as well as subsequent variants.

Understanding how the body responds to infection can help you make an informed decision about what to do to prevent severe illness and spreading this virus further: get vaccinated. Even if the COVID-19 virus continues to mutate in the future, vaccines support T-cells in minimizing infection.