People who have received two doses of the Pfizer vaccine have been found to have strong T-cell responses against the Kent and South African variants of Covid, suggesting that the vaccine will continue to protect against serious disease in the coming months.
In the first study to test immune responses against the variants circulating in populations, researchers found that although antibody responses against the new variants were blunted, they may still be high enough to protect most people from becoming infected, after a second dose of vaccine has been given.
Although previous studies had suggested that antibodies from those vaccinated with the Pfizer/BioNTech jab could recognise and neutralise viruses carrying some of the individual mutations found in the South African and Kent variants – albeit at slightly lower levels compared with previous variants – these were tested on engineered viruses rather than ones isolated from real patients.
These studies also did not look at T cells, which annihilate virus-infected cells and support the production of antibodies. Both immune responses help provide lasting protection after vaccination, but antibody responses are easier to measure.
“This virus hasn’t finished evolving, but I think that as long as the vaccines get rolled out, and people get those second doses, we’re going to be in a much better position by the summer than we are now,” said James.