The news: Two new sets of vaccine results announced today suggest the South African variant of the virus is proving harder to vaccinate against. US company Novavax today announced that its covid-19 vaccine was found to be 89% effective in final-stage clinical trials in the UK. But while the vaccine appears to protects people with the UK covid-19 variant, known as B.1.1.7, it was much less effective against the variant sequenced in South Africa, known as B.1.351. Another trial for the single-shot vaccine made by Johnson & Johnson today announced that its vaccine was overall 66% effective at preventing illness, but this dropped to just 57% in South Africa. That trial recruited thousands of South Africans between September and December, just as the dangerous variant was spreading widely.
The details: The Novavax Phase 3 trials enrolled more than 15,000 people aged between 18 and 84. The Novavax vaccine, which requires two doses, was 86% effective against the UK variant, but in the South African wing of the trial, where most people had the South African covid-19 variant, the vaccine was just 50% effective (similar to the level of protection conferred by most flu vaccines.) The UK has bought 60 million doses of the vaccine which will be produced locally. Novavax is a small US company that received $1.6 billion from the US government as part of “Operation Warp Speed.”
The (concerning) bigger picture: Novavax and Johnson & Johnson are not the only vaccine makers to discover their covid-19 shot is less effective against the South African variant. Moderna and Pfizer recently reported that their vaccines don’t work as well against this variant either, although manufacturers are confident that they would be able to quickly produce updated versions to combat the changing virus. The US reported its first known cases of the South African variant yesterday in two people in South Carolina. Those people had not had contact with one another, which suggests B.1.351 may already be spreading throughout the community in parts of the US.
Update: This story was updated to include the Johnson and Johnson trial results as they were announced.