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.

Novavax received clearance from the FDA to move forward with phase 3 clinical trials for its COVID-19-influenza combination (CIC) and standalone influenza vaccines. The FDA lifted a clinical hold that had been placed on Novavax's investigational new drug application after the company addressed concerns related to a serious adverse event reported in a phase 2 trial,