Phase III trials of Pfizer’s mRNA-based influenza vaccine begin

Leveraging their current mRNA vaccine technology developed during the COVID-19 pandemic, Pfizer have announced the start of phase III trials for a potential mRNA-based influenza vaccine.

Influenza is responsible for approximately 12,000–52,000 deaths in the United States alone every year. With different viral strains emerging each year, vaccines must continuously evolve and change to continue providing protection. Current vaccine technology relies on the growth of viruses in a culture, and killed with specific chemicals, producing inactivated vaccines. This process may require months to produce a viable vaccine. Even when currently available vaccine strains match that year’s circulating influenza strains, such vaccines may only provide 40%-60% protection. Predicting the next influenza season’s strain is a constant battle for global health experts and researchers. 

mRNA technology could allow future vaccine strains to change faster. Pfizer expects this flexibility, along with rapid manufacturing, to provide better strain matches in the future. In a potential pandemic situation, mRNA vaccines may allow for large-scale manufacturing of vaccines as they only require the genetic sequence of a virus. Pfizer’s mRNA vaccine is known as a modRNA vaccine, encoded with recommended strains for the Northern Hemisphere 2022–2023 cell culture- and recombinant-based influenza vaccines. Continuing from the phase II trials demonstrating safety and immunogenicity profiles, the phase III trial will focus on leveraging the mRNA technology in a vaccine to protect against more than the flu. The mRNA technology developed by Pfizer will be investigated for other applications outside the modRNA vaccine candidate. 

Annaliesa Anderson, Senior VP And CSO, Vaccine Research and Development at Pfizer, stated: “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 sever outcomes of viral disease like flu, including hospitalisation and death... We are excited to start the first phase III 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.” 

Source: Pfizer Initiates Phase 3 Study of mRNA-Based Influenza Vaccine | Pfizer