Phase III Study to Evaluate Safety and Immune Response of Two Formulations of Monovalent Influenza Vaccine A H5N8 in Adults

What this Trial Is About

Researchers are assessing the safety and immune response of two versions of a monovalent influenza vaccine candidate A H5N8 designed for adults and older adults. This vaccine, developed by the Instituto Butantan, aims to prepare for potential outbreaks of avian type AH5 influenza in humans. The study is a randomized, double-blind, placebo-controlled Phase III clinical trial focused on pandemic preparedness. Participants will receive one of two vaccine formulations, either containing 7.5 mcg or 15 mcg of hemagglutinin HA combined with the IB160 adjuvant, or a placebo of phosphate buffered saline. Each dose is 0.5 mL. The study will evaluate safety through the occurrence of local and systemic side effects within seven days after each vaccination and will assess the immune response 21 days following the second dose. During the trial, participants will be monitored for adverse events and reactions through diaries and clinical visits. Blood samples will be collected to measure seroprotection and seroconversion rates, indicating immune response. Safety assessments will continue for up to six months to record any serious or special interest adverse events. Participants are expected to comply with scheduled visits and procedures over the study period, which begins in September 2025 and ends in October 2027.

Safety and Immunogenicity of the Monovalent Influenza Vaccine A (H5N8) (Inactivated, Fragmented and Adjuvanted) in Adults and Older Adults