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

Inclusion Criteria: * a. Healthy participants aged between 40 and 79 years at the time of study entry, with or without a history of exposure to dengue fever; b. Agree to periodic contact by telephone, electronic means, and home visits and to the research center; c. Participants with reproductive potential must be using some effective contraceptive method at screening and continue using it for up to 90 days after the intervention; except in cases where the volunteer declares that she is not at risk of becoming pregnant, either by not engaging in sexual activities or by engaging in them in a non-reproductive manner, up to 90 days after vaccination; d. Demonstrate intent to participate in the study, documented by the participant's signature of the informed consent form, as well as the study procedures, including completing the Participant Diaries, blood collection, and being available for scheduled study visits and contacts. Exclusion Criteria: * a. For female participants with reproductive potential: pregnancy (confirmed by positive β-hCG test), breastfeeding or manifest intention to have sexual practices with reproductive potential without using a contraceptive method in the 90 days following vaccination; b. Planned donation of blood, semen or eggs in the 90 days following vaccination; c. Evidence of active uncontrolled neurological, cardiac, pulmonary, hepatic or renal disease according to anamnesis or physical examination, at the discretion of the investiga…