Pfizer initiates Phase 3 Study of mRNA-based Influenza vaccine

New Delhi: Pfizer Inc. has dosed the first participants in a pivotal Phase 3 clinical trial to evaluate the efficacy, safety, tolerability and immunogenicity of the company’s quadrivalent modified RNA (modRNA) influenza vaccine candidate in approximately 25,000 healthy U.S. adults.

“For years, there has been a need to better address the burden of influenza, despite the use of existing seasonal flu vaccines. Our experience with RNA viruses and mRNA technology has given us an even deeper understanding of the opportunity to potentially provide more efficacious vaccines that could further reduce the yearly rates of the severe outcomes of viral disease like flu, including hospitalization and death,” said Annaliesa Anderson, Ph.D., Senior Vice President and Chief Scientific Officer, Vaccine Research and Development, Pfizer.

“We are excited to start the first Phase 3 efficacy study of an mRNA-based influenza vaccine that could potentially deliver an improved flu vaccine to help address the significant burden of this disease,” added Anderson.

Each year, even when currently available vaccine strains match circulating influenza virus strains well, those vaccines typically confer only 40% to 60% protection, with even lower protection in years with poor matching of strains. With circulating influenza strains continually changing, predicting the best match for the next season’s vaccine is difficult for global health experts as those strains are chosen more than six months before the start of the influenza season that they target.

The flexibility of mRNA technology and its rapid manufacturing could potentially allow better strain matches in future years, and in a pandemic influenza situation, mRNA technology could allow rapid, large-scale manufacturing of vaccines. mRNA-based influenza vaccines require only the genetic sequence of the virus.

Influenza annually causes 140,000 to 710,000 hospitalizations, 12,000 to 52,000 deaths and about $25 billion in economic loss in the U.S. The impact of flu on racial and ethnic minority groups in the U.S. is even larger. Black Americans are 1.8 times more likely than their white counterparts to be hospitalized for flu while Latino and Indigenous Americans are 1.2 and 1.3 times more likely, respectively.

Although vaccination remains one of the best ways to help prevent infection and serious illness, racial and ethnic minority communities in the U.S. continue to be vaccinated at lower rates, and clinical trial enrollment for new or improved vaccines tend to lack diversity.