Novavax’s Covid-19 vaccine nearly 90% effective in U.K. study, much less in South Africa

Novavax Inc. said Thursday its Covid-19 vaccine candidate was found to be 89.3% effective based on interim data from its clinical trial in the United Kingdom — where a new variant of the virus originated. The results make Novavax’s candidate, called NVX-CoV2373, “the first vaccine to demonstrate not only high clinical efficacy against Covid-19 but also significant clinical efficacy against both the rapidly emerging U.K. and South Africa variants,” President and CEO Stanley Erck in a statement. Novavax…