FluGen’s Intranasal M2SR Vaccine Plus High Dose Outperforms Flu Shot in Older Adults

FluGen, Inc., a company specializing in vaccine development for respiratory diseases, revealed the promising results of its recent study in the journal Lancet Infectious Diseases. The study focused on the combined use of the intranasal M2SR vaccine and the Fluzone High Dose vaccine in adults aged 65-85. This age group is considered particularly vulnerable to influenza-related complications.

The research aimed to compare the safety, tolerability, and immune response generated by FluGen’s investigational M2SR influenza vaccine and Sanofi’s Fluzone High Dose inactivated influenza vaccine (IIV). The study's significance is underscored by the limitations of current flu vaccines, which primarily induce hemagglutinin (HA) antibodies and tend to have only moderate effectiveness during flu seasons.

This study, funded by the U.S. Department of Defense, involved older adults receiving either the M2SR vaccine, the Fluzone High Dose vaccine, or a combination of both. The results showed a synergistic immune response when the vaccines were used together, addressing an unmet need for more effective flu vaccinations in this population.

Dr. Robert Belshe, a founder of Saint Louis University’s Center for Vaccine Development, highlighted the ongoing struggle against influenza, particularly for older adults. He noted that current vaccines often fall short in terms of longevity, mutation protection, and preventing the initial infection in the upper respiratory tract. The study's findings suggest that the combined approach of using M2SR with the Fluzone High Dose vaccine might offer a solution, potentially saving millions from severe illness or death.

Intranasal vaccines like M2SR provide a primary defense at the infection site, preventing the virus from entering the nasal mucosa. M2SR has been effective in eliciting mucosal antibodies and protecting against various strains, while traditional flu shots generate antibodies in the bloodstream to combat the virus after infection. The combination of these two approaches offers enhanced protection against influenza.

The study demonstrated that M2SR significantly increased mucosal antibodies in nasal passages, serum antibodies against both matched and drifted influenza strains, and cellular immune responses compared to Fluzone High Dose and placebo. Previous studies have shown that while intramuscular vaccines generate strong antibody responses, only intranasal M2SR triggers comprehensive mucosal, cellular, and serum immunity.

FluGen’s President and CEO, Paul Radspinner, emphasized the growing acceptance of delivering two vaccines simultaneously. This method could potentially improve health outcomes by reducing the likelihood of infection and severe illness. Radspinner also highlighted the potential for this approach to bolster defenses against future influenza pandemics, such as H5N1, by combining intranasal vaccines with strong antibody-based injections.

The Phase 1b study, titled FluGen H3N2 v006, was a randomized, double-blind, placebo-controlled trial involving over 300 healthy older adults. Participants received either M2SR alone, the high dose IIV alone, both vaccines, or a placebo. The primary goal was to assess the safety and tolerability of the M2SR vaccine, delivered intranasally, alone or in conjunction with the high dose IIV, delivered intramuscularly. Secondary objectives included evaluating the antibody responses to various influenza strains, while exploratory endpoints examined additional immune parameters such as T-cell responses.

The study was supported by the Department of Defense through a significant funding award. FluGen continues to explore the potential of its M2SR vaccine, not only for influenza but also as a vector for other respiratory diseases, including COVID-19 and RSV.