Study finds T cell that recognizes COVID variants

T Cell micrograph
Scanning electron micrograph of a human T cell from the immune system of a healthy donor. NIAID

ROCKVILLE, Md. — Despite concerns regarding COVID variants, researchers at the National Institute of Allergy and Infectious Disease found an active T cell in blood samples of 30 people who had previously contracted and recovered from the virus before the variants emerged.

When SARS-CoV-2 (the virus that causes COVID-19) variants surfaced in late 2020, concerns arose that they would elude protection from prior infections or vaccines, potentially making reinfection more likely or vaccines less effective. However, researchers found one T cell, CD8+, that remained active against the virus.

Led by NIAID’s Andrew Redd, Ph.D., including scientists from Johns Hopkins University School of Medicine, Johns Hopkins Bloomberg School of Public Health and the Immunomics-focused company ImmunoScrape, they investigated whether CD8+ T cells, infected with the initial virus, could recognize three variants, including B.1.1.7 that was first detected in the United Kingdom.

In their study, researchers determined that the T-cell’s responses remained largely intact and could recognize virtually all mutations in the variants studied.

While larger studies are needed, the researchers noted that their findings suggest that T cell response in people who have recovered and vaccines are largely not affected by the mutations in the three variants, and should offer protection against emerging variants.

The authors indicated that optimal immunity to the virus likely requires strong multivalent T-cell responses in addition to neutralizing antibodies and other responses to protect against current strains and emerging variants. They stressed the importance of monitoring T-cell responses in recovered and vaccinated people as part of any assessment to determine if booster vaccines are needed.