Novavax COVID-19 vaccine works, but less so against variants

Novavax Inc. said Thursday that its COVID-19 vaccine appears 89% effective based on early findings from a British study and that it also seems to work- though not as well- against new mutated versions of the virus circulating in that country and South Africa.

The announcement comes amid worry about whether a variety of vaccines being rolled out around the world will be strong enough to protect against worrisome new variants - and as the world desperately needs new types of shots to boost scarce supplies.

The study of 15,000 people in Britain is still underway. But an interim analysis found 62 participants so far have been diagnosed with COVID-19 - only six of them in the group that got vaccine and the rest who received dummy shots.
The infections occurred at a time when Britain was experiencing a jump in COVID-19 caused by a more contagious variant. A preliminary analysis found over half of the trial participants who became infected had the mutated version. The numbers are very small, but Novavax said they suggest the vaccine is nearly 96% effective against the older coronavirus and nearly 86% effective against the new variant. The findings are based on cases that occurred at least a week after the second dose.

"Both those numbers are dramatic demonstrations of the ability of our vaccine to develop a very potent immune response," Novavax CEO Stanley Erck said in a call with investors late Thursday.
Scientists have been even more worried about a variant first discovered in South Africa that carries different mutations. Results from a smaller Novavax study in that country suggests the vaccine does work but not nearly as well as it does against the variant from Britain.

The South African study included some volunteers with HIV....