Oxford / AstraZeneca and Pfizer / BioNTech’s Covid-19 vaccines may be more effective against the Brazilian variant of the coronavirus than previously thought, according to a new study.
Research from the University of Oxford, which has not yet been peer-reviewed, has measured levels of antibodies that can neutralize or stop circulating variants, including those from South Africa and Brazil.
It has been found that vaccines against the variants do not work as well as against an original strain of coronavirus, but the Brazilian variant P1 may be less resistant to vaccine-induced antibodies than initially feared.
The South African variant remains the most worrying, the study found, and should be the focus of attention for manufacturers making new vaccines.
Professor Gavin Screaton, senior scientist on the paper, said, “This study broadens our understanding of the role of changes in spike protein in escaping the human immune response, measured as neutralizing antibody levels.
“The results suggest that P1 may be less resistant to vaccination and convalescence immune responses (Covid infection) than B1351 (South Africa) and similar to B117 (Kent).”
The study used blood samples from people with natural antibodies generated from Covid-19 infection and from people whose antibodies were induced by the Oxford or Pfizer vaccines.
An almost three-fold decrease in the level of virus neutralization by the antibodies produced by the Oxford and Pfizer vaccines for the Kent and Brazil variants compared to an original strain was noted.
The vaccines struggled more with the South African variant, with the level of virus neutralization reduced by seven to nine times in this variant.
Professor Andrew Pollard, Principal Investigator of the Oxford University Vaccine Study, said, “These continued efforts to investigate the link between changes in the virus and human immunity provide new evidence that will help us prepare for further health challenges from the pandemic Virus when we need it. “
Cases of the Brazilian and South African variants have been found in the UK, using surge covid tests to prevent their spread.