Novavax COVID-19 vaccine shows 96.4% efficacy, less protection against variants

The Maryland-based biotech Novavax has announced its COVID-19 vaccine candidate has 96.4% efficacy against COVID-19 illness from the original strain, sliding to 86.3% against the U.K. variant and falling to 48.6% in South Africa amid circulation of another concerning coronavirus variant. 

"We are very encouraged by the data showing that NVX-CoV2373 not only provided complete protection against the most severe forms of disease, but also dramatically reduced mild and moderate disease across both trials," Stanley C. Erck, president and chief executive officer of  Novavax, wrote in part in a news release posted Thursday. "Importantly, both studies confirmed efficacy against the variant strains." Findings from a Phase 3 trial in the U.K. drew from over 15,000 participants aged 18 to 84, 27% of whom were above age 65. Novavax noted 106 cases cropped up, 96 of which occurred in the placebo group. There were five severe COVID-19 cases, all in the placebo group and mostly attributed to the B.1.1.7 variant.