LONDON – The vaccine developed by the University of Oxford and AstraZeneca PLC is effective against a new highly transmissible variant of the virus that causes Covid-19, according to an analysis that offers more guarantees that a worldwide vaccination campaign will help end the disease. pandemic.
Still, the small-scale study showed that the vaccine works best against older, more established versions of the virus, which has so far been linked to nearly 2.3 million deaths worldwide and more than 100 million cases.
In a study published online on Friday, the researchers examined blood samples from about 256 participants in a continuous clinical trial of the vaccine that tested positive for Covid-19. The findings are preliminary and have not been formally reviewed by other scientists.
Genetic sequencing allowed them to identify which participants were infected with the new variant and who had an older version. A little less than a third had the new variant.
Variant of Coronavirus in the United Kingdom
By testing levels of antibodies and other markers of immune system activity against the virus, the researchers found that the vaccine elicited an effective immune response against the new variant in 75% of cases showing symptoms of infection and in about two-thirds of the cases. cases if those without symptoms were also included.
For those with the oldest strain, the vaccine was effective in 84% of symptomatic cases and 81% of all cases.
The researchers reported markedly different antibody responses between the two groups, saying that vaccine-induced antibodies were up to nine times less effective in neutralizing the new variant than the old ones. The general protection was similar, however, suggesting that other parts of the immune system are playing a key role, the study said.
“The vaccine’s effectiveness has been preserved against the new variant,” said the researchers.
The emergence of more contagious variants of the virus has sparked new waves of infection in various parts of the world, and has raised concerns that the virus may escape the vaccines that are now being launched in much of the world.
The latest findings from Oxford and AstraZeneca add signs that, for now, this does not seem to be the case. Pfizer Inc.
and Modern Inc.
reported that their vaccines are also effective against new variants, citing similar laboratory tests.
As new variants of the coronavirus spread around the world, scientists are racing to understand how dangerous they can be. WSJ explains. Illustration: Alex Kuzoian / WSJ
Write to Jason Douglas at [email protected]
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