Trial finds Oxford-AstraZeneca vax offers minimal protection against B.1.351 variant

South Africa has paused its rollout of the Oxford-AstraZeneca COVID-19 vaccine after new data suggested that the vaccine offers little protection from mild or moderate illness caused by the more contagious virus variant B.1.351.

The B.1.351 variant, first identified in South Africa, has now been found in at least 41 countries, including the U.S., according to the World Health Organization. Scientists say the variant accounts for 90% of new COVID cases in South Africa.

The trial, which involved around 2000 participants, was conducted by researchers at the University of the Witwatersrand in South Africa and the UK's Oxford University. The trial found that the vaccine offered "minimal protection" against mild and moderate cases. Further testing is needed to determine if the vaccine will still be effective at preventing severe cases caused from the variant.

The data, was disclosed at a news conference yesterday and has not yet been peer reviewed.

University of Oxford researchers said they are working to produce a new version of the vaccine that can protect against the most dangerous mutations of the B.1.351 variant, and hope to have it ready by this fall.

Read the NYT coverage