On Jun. 30, 2021, Novavax announced the publication of results from the final analysis of a pivotal Phase 3 clinical trial of its COVID-19 vaccine candidate conducted in the United Kingdom in the New England Journal of Medicine (NEJM).

The final analysis confirmed an overall efficacy of 89.7% with over 60% (half) of the cases caused by the B.1.1.7 (Alpha) variant, and a 96.4% efficacy against non-B.1.1.7 (non-Alpha) variants which represented strains most similar to the original virus.