Pfizer started its 25,000-person phase 3 trial Sept. 14 to test the efficacy of a flu vaccine candidate that uses the same mRNA technology as its COVID-19 vaccine. In mid-June, Moderna began enrolling 6,000 participants for its late-stage trial.
The Cambridge, Mass.-based drugmaker did not specify a projected timeline for when the new flu vaccine could be on the market, while Moderna CEO Stéphane Bancel said earlier this summer that he expects its candidate to be commercially available "over the next two to three years."
In late August, Moderna filed suit against Pfizer for its use of mRNA technology, which paints an uneasy backdrop as they work to prove efficacy in other mRNA vaccines.