Scientists, researchers, and healthcare professionals have long dreamed of a universal influenza vaccine: a vaccine that will protect against any strain of influenza. The dream took one step closer to reality with the initiation of a Phase I clinical trial at the National Institutes of Health (NIH), announced April 3, 2019. A universal vaccine would protect vaccinated individuals even when the seasonal circulating strains don’t match those predicted to be most widespread.

The vaccine, called H1ssF_3928, will undergo assessment for safety and immunogenicity in people. Volunteer subjects are currently being recruited and will be tested for vaccine tolerability and immune response to vaccination. Antibodies from vaccinated subjects will be tested for neutralization of the H1 influenza A virus (IAV) on which the vaccine is based, as well as neutralization of IAVs with other hemagglutinin types. Previous studies have shown the conserved regions of H1 used in the vaccine, which use a self-assembling ferritin component to generate a nanoparticle delivery system, have produced broadly protective antibodies in animal models.

This isn’t the only ongoing clinical trial for a universal flu vaccine. A Phase 2 clinical trial is ongoing for a universal vaccine based on the influenza virus M protein, with a planned Phase 3 trial reported. The M protein is much more highly conserved between influenza virus strains; the prediction is that reactivity against this protein will be cross-protective against multiple influenza strains.

The predictions for clinical trial success among the scientific community are mixed. Michael Osterholm, Director of the University of Minnesota’s Center for Infectious Diseases Research and Policy, told STAT news “I don’t think we’re that close at all,” in response to a strategic plan to develop a universal vaccine released in March 2018 by the National Institute of Allergy and Infectious Disease. However, NIAID Director Anthony Fauci said in a press release that the new Phase 1 clinical trial “is a step forward in our efforts to develop a durable and broadly protective universal influenza vaccine.”

Further Reading:

• The Scientist: First Universal Influenza Vaccine to Enter Phase 3 Trial
• ClinicalTrials.gov: Two Doses of Multimeric-001 (M-001) Followed by Influenza Vaccine
• ClinicalTrials.gov: Dose, Safety, Tolerability, and immunogenicity of an Influenza H1 Stabilized Stem Ferritin Vaccine, VRCFLUNPF099-00-VP, in Healthy Adults