Immunogenicity and Safety of Butantan Quadrivalent Influenza Vaccine (Split Virion, Inactivated) in Infants and Children .

The study will be carried out in multiple sites in Brazil, using a community-based recruitment strategy. The study interventions are the Butantan Quadrivalent Influenza Vaccine (split virion, inactivated) in two dose scheme (QIV-IB/0.25ml and QIV-IB/0.50ml) and the active controls Butantan Trivalent Influenza Vaccine (split virion, inactivated) containing Influenza B virus - Victoria or Yamagata lineage (TIVV-IB and TIVY-IB), in a ratio 1:1:1:1. The study population is healthy infants and children aged 6 to 35 months and all participants will be followed up 6 months after the last vaccination.