NIAID Sponsors Clinical Trials to Combat Future Pandemics of H7N9

The National Institute of Allergy and Infectious Diseases (NIAID) is sponsoring 2 phase 2 clinical trials for a vaccine to prevent H7N9 influenza. The objectives of the clinical trials are to test different variables of the vaccine candidate, 2017 H7N9 IIV, including different dosage amounts, various vaccination schedules, and whether or not adjuvants improve immune responses.

The 2017 H7N9 vaccine, developed by Sanofi Pasteur, uses an inactive strain of the virus that was collected in 2017. Researchers are hopeful that the vaccine will protect against new strains of H7N9.

The first reports of H7N9 infection amongst humans occurred in China in 2013. The virus, a bird flu, has caused 6 additional waves of infection, affecting more than 1500 humans and creating a high mortality rate. The virus typically spreads to humans through infected poultry and does not usually travel from person-to-person easily. Infection could potentially result in a pandemic if the virus mutates because there is limited immunity among humans.

The first trial will explore the experimental vaccine at different doses and will also, in some cases, involve the AS03 adjuvant. The investigators are looking to recruit 420 volunteers between 19 and 64, along with 300 participants over the age of 65.

Each participant will be randomly placed in 1 of 5 groups. Three groups will receive various doses of an adjuvanted vaccine, while the remaining groups will receive an unadjuvanted vaccine. Each participant will be vaccinated once and then a second time, 21 days following the first injection. The participants will be monitored following each vaccination and will be evaluated through blood samples for the presence of H7N9 antibodies. Clinical staff, led by principal investigator Lisa A. Jackson, MD, will follow the participants for 1 year.

The second trial will evaluate the H7N9 vaccine with the AS03 adjuvant in conjunction with a quadrivalent seasonal influenza vaccine. Investigators, led by Kathleen M. Neuzil, MD, will use the seasonal influenza vaccine to determine whether the vaccine candidate has an effect on seasonal influenza as well. Participants in this trial will include 150 volunteers between 19-64, that will be divided into 3 groups. The first group, made up of 60 participants, will receive the H7N9 vaccine with the AS03 adjuvant and the quadrivalent seasonal influenza vaccine within a 15-minute period on the first day and then an additional dose of the adjuvanted H7N9, 21 days later. The second group, made up of 60 participants, will receive the seasonal influenza vaccine on the first day and 2 doses of the H7N9 adjuvanted vaccine on days 22 and 43. The third group, made up of 30 volunteers, will only receive the seasonal influenza vaccine. Similar to the previous trial, participants will be monitored for 7 days following each vaccination and blood samples will be analyzed for antibodies of both H7N9 virus and seasonal influenza, along will follow-up observations for 1 year. Additionally, some participants will be tested to see if the vaccine will be preventive as the H7N9 virus continues to evolve.

Although H7N9 has not been seen in the United States, NIAID is sponsoring these trials in order to be better prepared for future pandemics. “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, MD, in a press release, “These new clinical trials will build upon initial studies of earlier versions of an H7N9 vaccine candidate to provide a more detailed picture of its safety and ability to generate a protective immune response to current H7N9 strains.”