International – Pfizer doses first patients with mRNA-based influenza vaccine

Pfizer has begun dosing the first participants in a pivotal phase 3 clinical trial to evaluate its quadrivalent modified RNA (modRNA) influenza candidate in approximately 25,000 healthy US adults, the company announced.

Each year, even when currently available vaccine strains match circulating influenza virus strains well, those vaccines typically offer only 40% to 60% protection, with even lower protection in years with poor matching of strains, Pfizer noted in a statement.

Influenza causes 12,000 to 52,000 deaths in the US every year, but the strains used in vaccines have to be changed continually ahead of the flu season as circulating viruses keep evolving.

The company hopes that its influenza candidate could potentially allow better strain matches in future years, and in a pandemic influenza situation, due to the flexibility of mRNA technology and mRNA-based influenza vaccines would require only the genetic sequence of the virus…