A candidate SARS-CoV-2 vaccine from Novavax is about 90 percent effective in preventing COVID-19 in a trial conducted in the UK, the New York Times reports. However, it has an efficacy rate of less than 50 percent in a trial in South Africa, where a new viral variant has been found.
According to a press release from Novavax, the Phase 3 trial in the UK included more than 15,000 participants and the company's analysis indicates a vaccine efficacy rate of 89.3 percent. It further says the candidate vaccine — which is protein based — had an efficacy rate of 95.6 percent against the original viral strain and 85.6 percent against the UK variant strain.
But, its Phase 3 trial in South Africa of about 4,400 individuals indicated a lower efficacy rate of 49.4 percent. "Fifty percent is not as good as 100, but it's a damn sight better than zero," John Moore, a Weill Cornell Medicine virologist, tells the Times.
Still, Baylor College of Medicine's Peter Hotez tells it that the finding that the vaccine is less effective against an emerging variant is troubling. "We have to have the American people vaccinated by late in the spring or early summer to have any hope in preventing the South African and the UK variants from taking over," he adds.
The Guardian reports that Novavax now plans to develop a vaccine specifically against the South African variant.