NIH: Avian Flu Vaccine Candidate Works Better With Adjuvant
The National Institutes of Health (NIH) reported that results from its sponsored trial shows its investigational vaccine against H7N9 avian flu works best when teamed up with an adjuvant.
Data from the Phase 2 clinical trial, sponsored by the National Institute of Allergy and Infectious Diseases (NIAID) under the NIH, indicated that immune responses induced by the vaccine, regardless of dosage, were less effective when administered without the adjuvant. The vaccine was produced by Sanofi Pasteur from inactivated H7N9 virus grown in chicken eggs. The adjuvant MF59, currently unlicensed in the U.S., was produced by Novartis Vaccines.
Findings show that those who received the vaccine without the adjuvant demonstrated minimal immune response, mirroring an earlier clinical study wherein an investigational unadjuvanted H7 avian virus vaccine triggered little to no antibody response. On the other hand, those who received just one dose of the adjuvant at the time of their first vaccination demonstrated almost similar antibody responses compared with those who received multiple doses of the adjuvant. This suggests that only one dose of an adjuvant is needed with the first vaccine dose in order to elicit a strong immune response.
The first avian flu case was diagnosed in in China early last year, brought about primarily through contact with infected poultry. While the H7N9 strain does not sicken birds, it causes illness in humans that contract it. The World Health Organization recorded a total of 452 lab confirmed cases and says that the virus was responsible for 166 deaths.
NIAID Director Anthony S. Fauci notes, “Although this influenza virus does not currently spread easily from person to person, all novel influenza viruses have the potential to evolve to cause widespread illness or death. Therefore, it is prudent to conduct clinical trials such as this one to be prepared in the event of an H7N9 avian influenza pandemic.”
Results of the NIH-NIAID study were published in the latest issue of the Journal of the American Medical Association.