Novavax is already poised to benefit from a separate combined Covid-flu vaccine via a deal with Sanofi announed earlier this year. Under the $1.4 billion co-licensing agreement, announced in May, Sanofi will have the sole right to use Novavax's existing Covid-19 vaccine in combination with its own flu vaccine.

The U.S. Food and Drug Administration has lifted its clinical hold on a late-stage trial of Novavax's COVID-influenza and its standalone flu vaccines after a safety concern was found to be unrelated to the combination shot,