Pfizer's coronavirus vaccine does successfully neutralise the more contagious P.1 variant of the virus recently discovered in Brazil, MedicalXpress reports new research shows. Pfizer and its German partner BioNTech conducted the study with scientists from both companies and researchers from the University of Texas Medical Branch.
Blood samples from vaccinated individuals were tested against an engineered version of the Brazilian variant. The samples came from participants in late-stage trials for the vaccine and were taken between two to four weeks after they received their second dose. In the lab, the vaccine worked as well against the Brazilian variant as it did against the original virus.
Last year, the vaccine showed 95% efficacy against the less contagious coronavirus strain.
The newer variant was first detected in January and has since spread from the Amazonian city of Manaus to multiple countries, including the US.
Though experts have cautioned that these results need to be validated in “real life”, The Daily Telegraph reports that there is growing optimism that existing coronavirus vaccines will provide at least some protection against highly contagious new variants.
“I think it does bode well for real life data,” Danny Altman, a professor of immunology at Imperial College London, said. “This is all starting to fall into place now – variants such as P.1, among others, are certainly good at evading the response of some neutralising antibodies (which protect against COVID-19). “But when we see a good immune response to Pfizer or Moderna – both of which induce astronomically high antibody levels, even when knocked down a little – the response is still firmly in the protective range.”
Professor Beate Kampmann, director of The Vaccine Centre at the London School of Hygiene and Tropical Medicine added: “Itʼs reassuring to see this comprehensive assessment of vaccine-induced neutralising antibody against a variety of variants.
“However, we cannot simply extrapolate from the immune responses induced by the Pfizer vaccine to other vaccines… work is already going on to 'tweak' the vaccines for the boosters that are likely to be necessary with all COVID-19 vaccines.”
The report says the NEJM study also tested the Pfizer jab against virus modified to include spike protein mutations found in the variants detected in Kent and South Africa – B.1.1.7 and 501Y.V2.
Like P.1, the Pfizer shot generated high levels of neutralising antibodies when presented with B.1.1.7. However, there was “robust but lower” activity against 501Y.V2. Previous studies have also suggested that the Pfizer jab may be slightly less effective against the variant first found in South Africa.
The company has said it believes the jab still protects against disease, but has plans to test whether a third booster dose or a slightly tweaked vaccine may generate higher levels of neutralising antibodies.
[link url="https://medicalxpress.com/news/2021-03-pfizer-covid-vaccine-mettle-brazilian.html"]Full Medical Xpress report (Open access)[/link]
[link url="https://www.nejm.org/doi/full/10.1056/NEJMc2102017"]New England Journal of Medicine correspondence (Open access)[/link]
[link url="https://www.telegraph.co.uk/global-health/science-and-disease/pfizer-vaccine-effective-against-highly-infectious-brazil-variant/?WT.mc_id=e_DM1346848&WT.tsrc=email&etype=Edi_FPM_New_ES_Subs&utmsource=email&utm_medium=Edi_FPM_New_ES_Subs20210309&utm_campaign=DM1346848"]Full report in The Daily Telegraph (Restricted access)[/link]
See also MedicalBrief archives:
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[link url="https://www.medicalbrief.co.za/archives/moderna-modifying-covid-19-vaccine-to-protect-against-emerging-strains/"]Moderna modifying COVID-19 vaccine to protect against emerging strains[/link]
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