Phase 3B Study Comparing Safety and Immune Response of Butantan Dengue Vaccine in Adults Aged 40-59 and Older Adults Aged 60-79

What this Trial Is About

Researchers are conducting a Phase 3b, randomized, double-blind for ages 60-79 and open-label for ages 40-59, multicenter study to evaluate the safety and immune response of the Butantan Dengue vaccine in adults aged 40 to 79 years. The study compares the humoral immune response of elderly participants 60-79 years to that of adults aged 40 to 59 years, including those with or without previous dengue exposure. The goal is to assess whether the vaccines immune response in the elderly is not inferior to that in younger adults. Participants receive a single dose of the Dengue 1,2,3,4 attenuated vaccine or placebo, with three study groups elderly receiving vaccine, adults receiving vaccine, and elderly receiving placebo. The vaccine dose contains an approximate concentration of 103.0 PFU of each attenuated dengue serotype virus. The study will last one year to evaluate immune response duration and monitor adverse events. Surveillance for dengue, chikungunya, and Zika virus infections will occur throughout the study. Participants will undergo blood tests to measure antibody responses at Day 1, Day 42 7 days, and Day 364 28 days after vaccination. Safety will be monitored through reports of adverse reactions up to Day 22 3 days and throughout the study. Participants will be contacted periodically by phone, electronic means, and home visits. Researchers will analyze neutralizing antibody seroconversion and track serious adverse events, ensuring participants health and vaccine safety over the year-long follow-up.

Butantan-DV Vaccine in Elderly Populations (DEN-04-IB)