Progress is being made in the development of mRNA flu vaccines, with Pfizer’s candidate showing promising results in recent clinical trials. According to research published in the November 20, 2023 edition of the New England Journal of Medicine, Pfizer’s mRNA flu vaccine outperformed traditional vaccines during the 2022–2023 flu season.
The phase 3 trial involved more than 18,000 healthy adults aged 18 to 64 from the United States, South Africa, and the Philippines. Researchers evaluated the percentage of participants who contracted the flu at least 14 days after vaccination. Results indicated that the mRNA vaccine was about 35 percent more effective in preventing flu illness compared to the traditional vaccine.
The mRNA vaccine specifically targeted hemagglutinin, a protein essential for the influenza virus to enter human cells. This vaccine included components from four different flu strains, following the recommendations made by a committee of the World Health Organization (WHO) that identifies which strains to include for each flu season.
In addition to Pfizer’s findings, Moderna has also released phase 3 trial results for its mRNA flu vaccine, which is designed for adults aged 50 and older. This vaccine demonstrated a relative efficacy of approximately 27 percent compared to traditional flu shots, with nearly 41,000 participants from 11 countries involved in the study.
The need for effective flu vaccines is particularly urgent for individuals aged 65 and older, who face a higher risk of severe complications from the virus. The mRNA vaccine platform offers a potential solution, as it allows for a faster production turnaround. This agility could lead to better vaccine matches for circulating flu strains, addressing a significant challenge in traditional vaccine production, which currently requires up to six months after the WHO’s recommendations are made.
As the Northern Hemisphere approaches its flu season, there are early indications that a variant that emerged during the Southern Hemisphere’s season is affecting flu samples in England and Japan. Unfortunately, this variant appeared too late to be included in the current vaccine recommendations for the Northern Hemisphere.
The advancements in mRNA technology, initially propelled by the rapid development of COVID-19 vaccines, are paving the way for more effective influenza prevention strategies. As these clinical trials progress, the potential for mRNA vaccines to become a vital tool against the influenza virus becomes increasingly apparent.
