Vaccination vs. infection: understanding SARS-CoV-2

SARS-CoV-2 is the virus that causes COVID-19. Scientists at St. Jude are studying how vaccination against and infection with SARS-CoV-2 affects the immune system.

Antigens are molecules that help the immune system recognize infections. The immune system is exposed to antigens from vaccinations and infections. SARS-CoV-2 variants such as delta and omicron also change the antigens the virus presents.

Scientists studied how exposure to antigens before and after vaccination alters the immune response. They found that the order of exposure (whether vaccination or infection came first) influenced the immune response.

“Understanding the T-cell response to COVID-19 infection and vaccination is challenging, but essential to developing a long-term control strategy for this virus,” said Joshua Wolf, PhD, MBBS, Infectious Diseases. “Large studies that enroll people before they get COVID-19 are the only way to do this work well.”

They used a variety of tools and techniques, some of which the researchers created. The study also used data from the St. Jude Tracking Study of Immune Responses Associated with COVID-19.

“We’ve gained an important understanding of how this virus is evolving and mutating, and how our immune responses adapt to these changes,” said Paul Thomas, PhD, Immunology.

The findings were published in Nature Immunology.

Read the news release