AstraZeneca Covid-19 vaccine weaker against South African stress

The study, which included approximately 2,000 volunteers with an average age of 31 years, was too small and the participants were too young to draw broad conclusions about the overall efficacy of the vaccine in protecting against the disease caused by the coronavirus, especially if it concerns hospitalization or death. . However, the findings add to concerns that a mutating virus is making existing Covid-19 vaccines less effective and that shots need to be updated to protect against new strains of virus.

Johnson & Johnson and Novavax Inc.,

whose vaccines have yet to be approved in any country, have also found their injections to be less effective in recent human clinical trials in South Africa. But their vaccines were still found to be 50% or more effective in preventing mild or moderate cases of Covid-19 and even more powerful in protecting recipients from serious illness and hospitalization of the new strain.

Sunday’s press release about the AstraZeneca trial in South Africa gave no efficacy rate for the vaccine. The Johnson & Johnson trial in South Africa involved approximately 6,500 people, while the Novavax trial had 4,400.

Far and wide

Thirty-two provinces have reported cases of the coronavirus variant first emerging in South Africa.

Countries where the B1.351 variant has been found

UK

First case

reported

12 December

U.S

First case

reported January 27

South Africa

First case reported on October 8

UK

First case

reported

12 December

U.S

First case

reported January 27

South Africa

First case reported on October 8

UK

First case

reported

12 December

U.S

First case

reported January 27

South Africa

First case reported on October 8

U.S

First case

reported

January 27

South Africa

First case reported on October 8

The University of the Witwatersrand in Johannesburg, which conducted the AstraZeneca study, said it could not assess whether the vaccine provided protection against more severe cases of Covid-19, as the relatively young study participants had a low risk of developing severe Covid-19. develop. -19 symptoms.

Still, the lead investigator of South African trials and University of Oxford scientists who co-developed the vaccine with AstraZeneca said that, based on the results of other vaccine studies, they were optimistic that their injection would protect against severe Covid-19.

“This study confirms that the pandemic coronavirus will find ways to further spread among vaccinated populations, as expected,” said Andrew Pollard, director of the Oxford Vaccine Group at the University of Oxford, in the press release of the study results. “But given the promising results of other studies in South Africa using a similar viral vector, vaccines could continue to ease the toll on healthcare by preventing serious illness.”

A spokesman for AstraZeneca said the company believes “our vaccine can protect against serious diseases.”

The South African tribe, known as B.1.351, is already responsible for most of the infections in South Africa and has been blamed for a surge in Covid-19 cases in countries like Mozambique and Zambia in recent weeks.

Researchers in the US, Canada, Israel, and a number of European and African countries have also detected it in positive coronavirus test samples from people without a recent travel history, suggesting that it is spreading in the community. In total, it has been identified in 32 countries, and virologists say it is likely to be present in other countries that do not perform systematic sequencing of positive test samples.

Scientists in South Africa and the UK believe the B.1.351 strain is about 50% more contagious than previous versions of the virus, based on the much faster increase in Covid-19 infections during South Africa’s second wave compared to the first and biological studies of changes in the structure of the virus.

South African researchers have said the B.1.351 variant does not appear to lead to more deaths or more serious cases of Covid-19.

Ravi Gupta, professor of clinical microbiology at Cambridge University who was not involved in the South African AstraZeneca vaccine trial, said Sunday’s results underscore the need to update the current crop of Covid-19 vaccines against the new variants. Still, he said, he expects the AstraZeneca footage will still provide some protection against the new strain. “We definitely still need to use the vaccines to protect people from serious diseases,” he said.

Concerns about the South African variant and its impact on vaccine efficacy have centered on a mutation known as E484K. Researchers think this mutation makes it more difficult for antibodies to get a grip and neutralize the virus.

The same mutation has also been found in a separate variant discovered in Brazil. Researchers in the UK said earlier this month that they have found the E484K mutation in a small number of patients infected with another fast-spreading variant of coronavirus that causes infections there.

—Jenny Strasburg contributed to this article.

Write to Gabriele Steinhauser at [email protected]

Write to Gabriele Steinhauser at [email protected]