Novavax Inc has reported that its protein-based Covid-19 vaccine achieved an efficacy rate of 89.3% in a Phase 3 trial conducted in the UK, even as a new strain of the virus was circulating in that country. Meanwhile, a separate Phase 2b study of the same vaccine achieved a 60% efficacy rate in South Africa in a study population that was HIV-negative. For the overall trial population, including those with and without HIV, the efficacy rate was 49.4%.
