Phase 1 trials of universal influenza vaccine candidate FluMos-v2 have begun at the National Institutes of Health Clinical Center in Bethesda. The trial, sponsored by the National Institute of Allergy and Infectious Diseases, will evaluate the vaccine's safety and potential for immune responses. FluMos-v2 is an upgraded version of FluMos-v1 and is designed to provide broader immunity against six influenza viruses.
The National Institutes of Health Clinical Center in Bethesda, Maryland, has begun a Phase 1 clinical trial of a new universal influenza vaccine candidate. The trial, sponsored by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH), will evaluate the safety of the investigational vaccine and its ability to elicit an immune response.
Current influenza vaccines
Currently, available seasonal influenza (or "flu") vaccines are effective against specific strains of influenza. Vaccines are re-evaluated and changed each year to best match the influenza strains expected to be most dominant in the upcoming flu season. Most seasonal flu vaccines are designed to train the immune system to protect against three to four different common flu viruses, but a "universal" flu vaccine may one day protect against even more strains.
"The ideal universal influenza vaccine could be administered less frequently than once a year and protect against multiple influenza strains. With each new universal influenza vaccine candidate and clinical trial, we are one step closer to this goal," said Hugh Auchincloss, MD, acting director of NIAID.
About the vaccine candidate FluMos-v2
The vaccine candidate under investigation, FluMos-v2, was designed by researchers at the NIAID Vaccine Research Center (VRC). FluMos-v1 began its first human trials in 2021 and is still in trials. FluMos-v2 is designed to induce antibodies against multiple different strains of influenza virus by displaying portions of the influenza virus hemagglutinin (HA) protein in a repeating pattern on a self-assembling nanoparticle scaffold. Exposure to these harmless viral protein fragments allows the immune system to recognize and fight the real virus. In animal experiments, the experimental vaccine produced a robust antibody response.
The FluMos-v1 vaccine candidate showed HA for four influenza viruses, while FluMos-v2 showed HA for six influenza viruses: four influenza A viruses and two influenza B viruses. Researchers expect this will further expand immunity in vaccine recipients, providing protection against a wider variety of influenza viruses.
Trial details and follow-up actions
The new clinical trial is expected to recruit 24 healthy volunteers aged 18-50, who will receive two intramuscular injections of the FluMos-v2 vaccine candidate. The interval between injections is 16 weeks. First, participants will be included in the low-dose group (60 micrograms per dose). If no safety concerns are found after at least three participants receive this dose of vaccine, recruitment will begin for participants in the higher-dose group (180 micrograms per dose). The research team plans to recruit 12 participants per dose group.
Participants will receive regular follow-up calls and check-ups for 40 weeks after their first dose to track their response to the experimental vaccine. Researchers will also take blood samples during the visits to measure the immune response to the vaccine candidate.