NIH to Evaluate Experimental Adjuvants for Seasonal Influenza Vaccine

The National Institutes of Health (NIH) is conducting an early-stage clinical trial to evaluate the safety and efficacy of two licensed seasonal influenza vaccines administered with or without novel adjuvants. Adjuvants are more likely to produce a stronger immune response to the vaccine, thus providing better protection. The two novel adjuvants being tested in the study have demonstrated promise in enhancing the immune response to influenza vaccines in animal models. Both were also shown to be well-tolerated when given in conjunction with either Flublok or Fluzone in additional animal models.

The Phase 1 trial will enroll 240 healthy adults between 18 years and 45 years at eight vaccine and treatment evaluation units comprised of a network of clinical trial sites funded by the NIH’s National Institute of Allergy and Infectious Diseases. During the 18-month trial, participants will be randomized to receive one dose of the Northern Hemisphere 2018-2019 influenza seasonal version of either Fluzone quadrivalent influenza vaccine or Flublok quadrivalent influenza vaccine administered alone or in combination with either the AF03 or the Advax CpG55.2 adjuvant. Participants will then be required to return to the clinic for regular visits for at least 57 days to be evaluated for adverse effects and to collect blood samples to track vaccine-related immune responses. Ninety days after vaccination, all volunteers will receive a dose of the 2019-2020 seasonal quadrivalent influenza vaccine without adjuvant and will be observed for adverse effects. Those who received Fluzone initially will receive the updated Fluzone vaccine, and those who received Flublok will receive the updated Flublok vaccine. At the final clinic visit one year after participants’ first vaccination, investigators will conduct a final blood draw and will ask for a total account of any adverse effects.

Investigators are hopeful the completed study will provide more information on the safety and immunogenicity of adjuvanted seasonal influenza vaccines. Specifically, they hope to determine the best combination of vaccine and adjuvant needed to provide robust immunity.