Universal flu vaccine developed by US government begins human trials
Researchers at the National Institutes of Health (NIH) are beginning a Phase 1 human trial to test a new universal flu vaccine. The trial will test the novel vaccine being delivered either as a nasal spray or by injection after animal studies demonstrated strong results.
“Influenza vaccines that can provide long-lasting protection against a wide range of seasonal influenza viruses as well as those with pandemic potential would be invaluable public health tools,” said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID). “The scientific community is making progress on this pressing global health priority.”
The novel vaccine has been dubbed BPL-1357 and is a multivalent, whole-virus vaccine containing inactivated copies of four particular strains of influenza: H1N9, H3N8, H5N1, and H7N3. The viruses have been inactivated using a chemical known as beta-propiolactone (BPL).
A preclinical study involving mice and ferrets found two doses of the experimental vaccine was 100-percent protective against fatal doses of six different strains of influenza. Promisingly, these animal studies also demonstrated the vaccine was equally effective when administered as a nasal spray compared to the more traditional intramuscular injection.
The Phase 1 trial will recruit up to 100 healthy subjects randomized into three groups: intranasal, intramuscular or placebo. The study will run for seven months and its primary goal will be to investigate immune responses and safety profiles from the novel vaccine.
“With the BPL-1357 vaccine, especially when given intranasally, we are attempting to induce a comprehensive immune response that closely mimics immunity gained following a natural influenza infection,” explained Matthew Memoli, an NIAID researcher leading the trial. “This is very different than nearly all other vaccines for influenza or other respiratory viruses, which focus on inducing immunity to a single viral antigen and often do not induce mucosal immunity.”
Memoli hopes the trial will establish the potential for this novel vaccine to not only generate broad antibody responses but also a more direct mucosal immune response in nasal cells exposed to the intranasal version of the vaccine.
Intranasal vaccines are a hot research topic at the moment, with plenty of work exploring how inhalable vaccines could effectively prevent respiratory viruses from taking hold at the point of entry into a human body. A number of intranasal COVID-19 vaccines are currently in development, with the suggestion they could prevent infection by training immune cells in the mucous membranes of the nose to recognize the virus and immediately kill it at first exposure.
Of course, this is far from the first research to try and crack the problem of a universal flu vaccine. The last few decades are littered with failed attempts, and there are several other universal flu vaccines currently in various stages of development. Nevertheless, Fauci is optimistic this candidate is as good as any previously floated.
“The BPL-1357 candidate influenza vaccine being tested in this clinical trial performed very well in pre-clinical studies and we look forward to learning how it performs in people,” Fauci said.