The delta variant may be more successful in evade protective response of vaccines Pfizer and AstraZeneca, indicated a study that published Plos and that does not include the new omicron.
A team of British scientists, led by the University of Glasgow, did an analysis to quantify the ability of the alpha, beta and delta variants to evade the immunity induced by these two vaccines.
The study indicated that both preparations conferred protection against Covid-19 variants, but they observed “less neutralization of antibodies“in beta and delta variants.
In the sample of vaccinated individuals, the delta variant reduced the immune response in recipients of the Pfizer and Astra Zeneca vaccine. 4.31 and 5.11 times respectively, Plos indicated.
The research was not designed to directly measure the efficacy of the vaccine, although was in line with the recent findings of Public Health England, on a slightly lower efficiency against the delta variant than with the preceding ones.
The researchers used serum samples from 156 people who had received two doses and 50 with only one, according to the publication summarizes
The team exposed the SARS-CoV-2 proteins in a virus model system to sera from vaccinated people and observed the response of the antibodies and measured how effectively these prevented each variant from infecting cells.
Vaccines are still very effective in preventing serious infection and death, but the authors noted that “continuous monitoring of neutralization against newer variants is indicated in conjunction with vaccine efficacy studies,” as the virus continues to evolve over time, especially in vulnerable groups “.
Mutations change the shape of the coronavirus spike protein (the one it uses to enter human cells) preventing the recognition of antibodies and allowing the virus to escape vaccine-induced immunity.
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