3-21-2023 7:40am

NIH: SARS-CoV-2 infection weakens immune-cell response to vaccination

Anita Johnson-Brown Editor

SARS-CoV-2 infection weakens immune-cell response to vaccination

SARS-CoV-2 infection weakens immune-cell response to vaccinationAnalysis of the Pfizer-BioNTech COVID-19 vaccine's response in individuals with a prior SARS-CoV-2 infection uncovered significantly lower volumes and quality of key immune cell reactions. These findings, recently published in Immunity, lead to the conclusion that prior virus infection damages an essential immune-cell response. However, vaccine recipients who have previously suffered from COVID-19 are more protected than unvaccinated patients. This research was conducted by Mark M. Davis, Ph.D., director of the Stanford Institute for Immunity, Transplantation and Infection and professor of microbiology and immunology at Stanford University School of Medicine in Palo Alto, California; he is also a Howard Hughes Medical Institute Investigator—with funding provided by NIAID as part of the National Institutes of Health.

Dr. Davis and colleagues developed an advanced tool that can identify particular T cells responding to SARS-CoV-2 or the Pfizer-BioNTech vaccine. These T cells coordinate the body's response to the virus and fight it by killing infected cells, which guards against COVID-19 symptoms. This tool was designed to analyze how CD4+ T cells and CD8+ T cells recognize certain parts of the virus’s spiky protein as well as other sites on SARS-CoV-2. The same parts of its spike protein are used in the Pfizer-BioNTech vaccine, stimulating immunity without causing infection. Scientists then examined samples from a group of people who were never infected but had gotten two doses of this vaccine.

A study conducted by researchers at the University of Tokyo found that subjects who had never been exposed to SARS-CoV-2 and received two doses of a vaccine developed robust CD4+ and CD8+ T-cell responses as well as multiple cytokines. Meanwhile, those who had been infected with SARS-CoV-2 but received no vaccine demonstrated considerably lower levels and functionality of spike-specific CD8+ T cells. Moreover, an even lower amount of these cells were observed in unvaccinated people with COVID-19 compared to vaccinated people with no prior exposure. These findings suggest the importance of thorough vaccination for achieving effective immunity against SARS-CoV-2.

The collective findings from the research team suggest that SARS-CoV-2 infection has a negative effect on CD8+ T cell immune responses, similar to those previously observed for viruses such as hepatitis C and HIV. This underscores the importance of developing vaccination strategies targeted at bolstering antiviral CD8+ T cell actions in individuals who have had prior coronavirus infections. Last updated on 03/20/2023 by Anita Johnson-Brown.

by Anita Johnson-Brown on 03/20/2023