From the WebMD Archives

Feb. 8, 2021 -- The COVID-19 vaccine developed by the University of Oxford and AstraZeneca doesn’t appear to work well against the coronavirus variant identified in South Africa, prompting health officials to stop using the vaccine in the country.

Scientists from the vaccine’s clinical trial said it didn’t protect participants from mild or moderate COVID-19, according to The New York Times. Previous infection from earlier versions of the coronavirus also didn’t seem to protect people from reinfection with the variant known as B.1.351.

“These results are very much a reality check,” Shabir Madhi, PhD, a virologist who ran the vaccine trial in South Africa, told reporters on Sunday.

In the clinical trial, about 2,000 participants received two doses of the vaccine or placebo shots. In the vaccine group, 19 were infected with the new variant. In the placebo group, 20 people were infected with the new variant. The minimal difference suggests that the vaccine doesn’t protect against the new variant.

However, since the scientists evaluated a low number of cases, it was difficult to assess how effective the vaccine may be against the variant, the news outlet reported. The clinical trial participants were mostly young and unlikely to develop severe COVID-19. Scientists also couldn’t determine whether the vaccine protects against severe illness, hospitalization, or death.

The new findings haven’t yet been peer-reviewed and will be submitted as a pre-print this week. If scientists find that the vaccine protects against the most severe COVID-19 cases, health officials may use the vaccine doses. About 1.5 million doses of the vaccine arrived in South Africa last week, which will now be stored until health officials analyze more data, according to CBS News. The doses, which don’t require the same cold storage as other COVID-19 vaccines, will expire in April.

Now health officials in South Africa will plan to vaccinate health care workers with the Johnson & Johnson vaccine, which has prevented severe COVID-19 and hospitalizations associated with B.1.351. The company has applied for an emergency use authorization in South Africa.

Researchers at the University of Oxford said they’re working on a new version of the vaccine that can protect against the variant. They hope it will be ready by the fall.

“This study confirms that the pandemic coronavirus will find ways to continue to spread in vaccinated populations, as expected,” Andrew Pollard, PhD, the chief investigator on the Oxford vaccine trial, said in a statement.

“But taken with the promising results from other studies in South Africa using a similar viral vector, vaccines may continue to ease the toll on health care systems by preventing severe disease,” he said.

Moderna has also begun developing a new version of its vaccine that could be a booster shot against the B.1.351 variant, The New York Times reported. Moderna and Pfizer have said that preliminary studies indicate their vaccines offer some protection against B.1.351, though at a lower rate than against the original version. Johnson & Johnson and Novavax have also reported some effectiveness against the variant. The U.S. is waiting on clinical trial data for the Oxford-AstraZeneca vaccine, which is expected in March.

The WHO will meet on Monday to discuss the Oxford-AstraZeneca vaccine, CBS News reported. The vaccine is scheduled to make up a large portion of the doses in the Covax global vaccine rollout that will serve low- and middle-income countries.

The B.1.351 variant has become the dominant form of the coronavirus in South Africa and has spread to 32 countries. The U.S. has reported six cases of the variant in Maryland, South Carolina, and Virginia, according to the latest CDC tally.

Show Sources

The New York Times: “AstraZeneca’s Vaccine Does Not Work Well Against Virus Variant in South Africa.”

CBS News: “South Africa halts vaccination plan as AstraZeneca shot appears less effective on variant there.”

University of Oxford: “ChAdOx1 nCov-19 provides minimal protection against mild-moderate COVID-19 infection from B.1.351 coronavirus variant in young South African adults.”

CDC: “U.S. COVID-19 Cases Caused by Variants.”

© 2021 WebMD, LLC. All rights reserved. View privacy policy and trust info