Existing COVID-19 vaccines are likely to protect against the Brazilian coronavirus variant, scientists at the University of Oxford, UK, have reported.
Pre-print data suggest that natural- and vaccine-induced antibodies can still neutralise variants that are circulating from South Africa, Brazil and elsewhere, but at lower levels. Their findings also suggest the P1 ‘Brazilian’ strain may be less resistant to these antibodies than first feared.
Lead study scientist Professor Gavin Screaton said: “This study extends our understanding the role of changes in the spike protein in escape from the human immune response, measured as neutralising antibody levels. The results suggest that P1 might be less resistant to vaccine and convalescent immune responses than B.1.351, and similar to B.1.1.7.”
In the pre-print publication, available on bioRxi, the authors report on the neutralisation of these strains when using blood samples from people who have developed natural antibodies following a COVID-19 infection and from those with antibodies generated from the Oxford-AstraZeneca and Pfizer-BioNTech vaccines.
The data show a nearly three-fold reduction in the level of virus neutralisation by the antibodies generated by the vaccines for the B.1.1.7 (Kent) and P.1 (Brazil) variants when compared to the original “Victoria” strain, and a nine-fold and 7.6-fold reduction respectively against the B.1.351 (South Africa) strain.
Professor Andrew Pollard, chief investigation on the Oxford University vaccine trial, said: “These further efforts to investigate the relationship between changes in the virus and human immunity provide new insights that help us be prepared to respond to further challenges to our health from the pandemic virus, if we need to do so.”
The authors write that because P.1 and B.1.351 contain similar changes in the receptor binding domain, it was assumed that the neutralising antibodies would be similarly affected, which would mean vaccination is likely to provide some protection against P.1.
The drop in vaccine efficacy against mild to moderate disease against B.1.351 is likely a reflection of the mutations occurring outside the receptor binding domain, they add.
They conclude that developing vaccine constructs to B.1.351 should be the greatest priority for vaccine developers globally.
* More than 75% of over-70s in England now have antibodies against COVID-19, highlighting the success of the vaccine programme, Public Health England reported yesterday.
Just 5.6% of the population had antibodies from natural infection, researchers found.
The agency said the findings suggested that most recipients had a strong response to their first dose of vaccine.
Its head of immunisation Dr Mary Ramsey said: “The latest data continue to show that both vaccines in use in the UK are still providing really good levels of protection against COVID-19. As well as reducing cases, if vaccinated people catch COVID-19, they are less likely to get serious illness and die.”
• The pandemic reduced projected life expectancy for men in England by more than a year, according to a new analysis.
The reduction for men was 1.3 years and for women 0.9 years, Public Health England said.
Dejnirattisai W, Zhou D, Supasa P et al. Antibody evasion by the Brazilian P.1 strain of SARS-CoV-2. bioRxiv 19 March 2021; doi: https://doi.org/10.1101/2021.03.12.435194
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