LONDON – The vaccine developed by Oxford University and AstraZeneca PLC is effective against a new highly transmissible variant of the virus that causes Covid-19, according to an analysis that provides additional assurance that global vaccination action will help end the pandemic.
However, the small-scale study showed that the vaccine works better 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 Friday, researchers examined blood samples from about 256 participants in an ongoing clinical trial of the vaccine that tested positive for Covid-19. The findings are preliminary and have not been officially reviewed by other scientists.
Genetic sequencing allowed them to identify which participants were infected with the new variant and who had an older version. Just under a third had the new variant.
Coronavirus variant from Great Britain
By testing antibody and other markers of immune system activity against the virus, the researchers found that the vaccine triggered an effective immune response against the new variant in 75% of cases with symptoms of infection and in about two-thirds of cases if including those that showed no symptoms.
For those with the older strain, the vaccine was effective in 84% of symptomatic cases and 81% of all cases.
The researchers reported abruptly different antibody responses between the two groups, saying the vaccine-induced antibodies were up to nine times less effective at neutralizing the new variant than the old one. Overall protection was similar, however, suggesting that other parts of the immune system play a key role, the study said.
“The effectiveness of the vaccine has been maintained against the new variant,” the researchers said.
The emergence of more contagious variants of the virus has led to new waves of infection in many parts of the world and raised concerns that the virus could escape vaccines that are now being released in much of the world.
The latest discoveries from Oxford and AstraZeneca add to the 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 coronavirus travel the world, scientists are vying to understand how dangerous they could be. WSJ explains. Illustration: Alex Kuzoian / WSJ
Write to Jason Douglas the [email protected]
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