By Study Shows T Cells From Recovered Patients Can Recognize New Variants
Are individuals who have recovered from the original COVID-19 strain more likely to be reinfected by the newer variants that have recently emerged? Or are the immune response of the patients able to recognize and fight these variants? Researchers investigate the possibility.
The study was conducted by researchers from the National Institute of Allergy and Infectious Diseases (NIAID), led by staff scientist Andrew Redd, Ph.D., and scientists from the Johns Hopkins University School of Medicine, Johns Hopkins Bloomberg School of Public Health, and ImmunoScape, a company focused in Immunomics.
Researchers collected blood cell samples from thirty (30) patients who have contracted and recovered from the original SARS-CoV-2 strain before the different variants emerged. They investigated whether the T Cells found in the blood samples of the patients will also be able to recognize the following variants: the B.1.1.7 variant, originally found in the United Kingdom; B.1.351, which was first detected in the Republic of South Africa; and B.1.1.248, which emerged in Brazil.
Since mutations in the spike protein of the virus, the part of the virus that it uses to attaches itself to the cell, could make it hard for the T Cells and neutralizing antibodies to recognize the virus and trigger an immune response, it could potentially make re-infection more likely or vaccination less effective.
However, in the study, they were able to determine that the CD8+ T Cell, which remained active in the patients’ immune response against the original strain of the virus, remained largely intact and could also recognize virtually all mutations in the variants studied.
“CD8+ T cells limit infection by recognizing parts of the virus protein presented on the surface of infected cells and killing those cells.” said the researchers.
Scanning electron micrograph of a human T lymphocyte (also called a T cell) from the immune system of a healthy donor. Photo Source: NIAID
Since the T Cell response in recovered and vaccinated individuals is not largely affected by the mutations in the three variants included in the study, it should offer them protection against the variants that are emerging, the findings of the study suggest.
Further studies are needed to examine the immune responses and whether a booster shot would be an effective solution against the emerging variants.
SOURCE: NIAID
