The U.S. government hopes to get an effective H7N9 avian flu vaccine ready in case of a pandemic. In its recent effort, two phase 2 trials sponsored by the NIH’s National Institute of Allergy and Infectious Diseases have started enrolling participants in the U.S. to test a candidate developed by Sanofi Pasteur.
Dubbed 2017 H7N9 IIV, the vaccine contains an inactivated H7N9 virus collected in 2017. Sanofi developed the candidate with help from the HHS’ Biomedical Advanced Research and Development Authority (BARDA). Scientists hope the new version could provide better immunity against a newly emerged strain of H7N9.
These phase 2 trials will last 16 months and will test the vaccine in different dosages, on different schedules, with or without GlaxoSmithKline’s AS03 adjuvant. One of the trials will also test the shot together with a quadrivalent seasonal flu vaccine to see whether it affects the other’s immune response.
Although H7N9 doesn’t spread easily from person to person at this point, scientists worry that it could happen after mutation and turn into a widespread pandemic. The CDC found last year that a mutated strain circulating in China wasn’t responsive to existing vaccines at the time, prompting the WHO to recommend that new candidates be developed.
“As we experience one of the worst seasonal influenza epidemics in recent years here in the United States, we also must maintain a scientific focus on novel influenza viruses, such as H7N9, that have the potential to cause a pandemic,” said NIAID Director Anthony S. Fauci, M.D., in a statement.
NIAID funded research on an older version of the vaccine developed by Sanofi right after the virus was first reported in humans in China in 2013. The agency reported in 2014 that that candidate works better with adjuvant.
Other than direct exposure to infected poultry or contaminated environments, people don’t easily get this bird flu. But because most people have little to no immunity to it, in five previous endemics in China, 39% of those infected died. As a member of the notorious influenza A family, H7N9 has so far resulted in 1,565 human infections and 613 deaths, according to the WHO. No human cases have been detected in the U.S.
Through another contract potentially worth $610 million that runs through 2021, BARDA is tasking Protein Sciences to develop two recombinant vaccine candidates. Such vaccines, manufactured in cells, could be developed faster than traditional egg-based vaccines, an advantage that could prove useful in the face of a pandemic. Now that program also belongs to Sanofi after the French pharma bought Protein in a $650 million-plus acquisition last August.
Moderna is also testing an mRNA-based H7N9 vaccine candidate in phase 1.