The Search for a Universal Flu Vaccine

By Jane Farrell

Researchers will begin testing on human subjects a universal influenza vaccine that would, with one shot, combat various flu strains, including those that could cause a pandemic.

The experimental vaccine, known as H1ssF_3928, was developed by scientists at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH). In the clinical trial, the scientists will examine the vaccine’s safety and tolerability as well as its ability to induce an immune response in healthy study volunteers.

According to the NIH, H1ssF_3928 is designed to teach the body to make protective immune responses against diverse influenza subtypes by focusing the immune system on a portion of the virus that varies relatively little from strain to strain. The vaccine candidate was developed as part of a broader research agenda to create a so-called “universal” influenza vaccine that can provide long-lasting protection for all age groups from multiple influenza subtypes, including some that might cause a pandemic.

“Seasonal influenza is a perpetual public health challenge, and we continually face the possibility of an influenza pandemic resulting from the emergence and spread of novel influenza viruses,” said NIAID Director Anthony S. Fauci, M.D. “This Phase 1 clinical trial is a step forward in our efforts to develop a durable and broadly protective universal influenza vaccine.”

The clinical trial is being conducted at the NIH Clinical Center in Bethesda, Maryland. It is being led by Grace Chen, M.D., of NIAID’s Vaccine Research Center (VRC) Clinical Trials Program.

The study subjects will not be exposed to any influenza virus.

The trial will gradually enroll at least 53 healthy adults aged 18 to 70 years. The first five participants will be aged 18 to 40 years and will receive a single 20-microgram (mcg) intramuscular injection of the experimental vaccine. The remaining 48 participants will receive two 60-mcg vaccinations spaced 16 weeks apart. They will be stratified by age into four groups of 12 people each: 18 to 40 years, 41 to 49 years, 50 to 59 years, and 60 to 70 years. Investigators hope to understand how participants’ immune responses to the experimental vaccine may vary based on age and the likelihood of their previous exposure to different influenza variants.

Study participants will be asked to record their temperature and any symptoms on a diary card for one week after each injection. They also will be asked to visit the clinic to provide blood samples at specific times. Investigators will test the samples in the laboratory to characterize and measure levels of anti-influenza antibodies, which are potentially indicative of immunity against influenza. Participants will return for nine to 11 follow-up visits over 12 to 15 months. They will not be exposed to any influenza virus as part of the clinical trial.

“This Phase 1 clinical trial is the culmination of years of research and development made possible by the unique collaborative setting that the VRC offers by bringing together top scientists, manufacturing expertise, and an outstanding clinical team,” said VRC Director John Mascola, M.D.

The VRC expects the clinical trial to complete enrollment by the end of 2019 and hopes to begin reporting results in early 2020. For more information about the trial, click here to visit the government’s clinical trials site and use the search identifier NCT03814720.