AstraZeneca and Pfizer Covid vaccines more effective against the Brazilian variant than initially feared

The coronavirus vaccines being launched in Britain work better against the Brazilian variant than initially feared, the research suggests.

A study by the University of Oxford found that its vaccine and the jab made by Pfizer work just as well against the P.1 strain that first appeared in Manaus as against the Kent variant.

The vaccines, already in the arms of 25 million Britons, have proven highly effective against the dominant Kent strain in the UK, reducing deaths and hospital rates by more than 85 percent.

Scientists initially feared that the P.1 variant was resistant to vaccines because it has a number of worrying mutations in addition to those it shares with the Kent strain.

There have already been 12 cases of the Brazilian variant in the United Kingdom – nine in England and three in Scotland. All patients had direct or indirect calls to travel to Brazil.

The study exposed blood samples from vaccinated people to various variants of Covid and monitored their antibody responses.

He found that vaccines produced almost three times less antibodies against the Kent and Brazil variants when compared to the original strain. The researchers said that this is still more than enough to neutralize the viruses.

However, jabs stimulated up to nine times less antibodies when exposed to the South African variant, which was detected in hundreds of people in the UK.

But antibodies are not the only part of the immune response to Covid – white blood cells also play an important role, which means that even if vaccines do not produce a strong antibody response, they must still prevent serious diseases.

Vaccine manufacturers said earlier that vaccines will still prevent the vast majority of people from getting sick with this strain.

They say that in the few vaccinated people who still contract the virus, their symptoms will be reduced to “sniffles”.

Professor Gavin Screaton, the medical expert who led the research, said: ‘This study expands our understanding of the role of changes in the peak protein in escaping the human immune response, measured as neutralizing antibody levels.

‘The results suggest that P1 may be less resistant to vaccines and convalescent 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 a Covid-19 infection and those whose antibodies were induced by the Oxford or Pfizer vaccines.

He found a nearly three-fold reduction in the level of neutralization of the virus by antibodies generated by the Oxford and Pfizer vaccines for the Kent and Brazil variants compared to an original strain.

“These data suggest that natural and vaccine-induced antibodies may still neutralize these variants, but at lower levels,” said the university.

‘It is important to note that the’ Brazilian ‘P1 strain may be less resistant to these antibodies than initially feared.’

The vaccines struggled more with the South African variant, with a seven-fold reduction in the level of neutralization of the Oxford vaccine virus and a nine-fold reduction for Pfizer.

Professor Andrew Pollard, chief investigator for the Oxford University vaccine trial, said: ‘These additional efforts to investigate the relationship between changes in the virus and human immunity provide new insights that help us to be prepared to respond to new challenges. to our health arising from the pandemic virus, if we need to do that. ‘

Cases of the Brazilian and South African variants have been found in the United Kingdom, with peak Covid tests employed to help prevent its spread.

Public Health England data show that there were 344 cases of the South African strain and 12 cases of the Brazilian version.

The agency has six variants ‘under investigation’ – including strains from the Philippines and Antigua and several that have spread across the UK.

There are four more that he describes as ‘variants of concern’. They are: the current dominant Kent strain (B.1.1.7); one imported from Brazil (P.1), the South African variant (B.1.351) and a version of the Kent strain that evolved even more than it appeared in Bristol.

Although new variants appear in the UK and around the world more often, leading scientists have warned against “obsession” with mutant viruses.

All major vaccine manufacturers say they are confident that their jabs will be highly effective against all emerging strains.

Researchers at the University of Oxford said that a single strain is unlikely to make vaccines significantly weaker in the next year.

Instead, they say there is more chance that a series of developments over the course of many months or even years could eventually make the current crop of jabs less potent.

But vaccines can be modified in a matter of weeks and regulators in the UK, the USA and the EU have passed laws, meaning that new booster vaccines can be approved quickly.