 The study evaluated the immunogenicity and safety of Northern Hemisphere 2015-2016 formulations of quadrivalent splitvirion inactivated influenza vaccine, IIV4, and licensed splitvirion trivalent inactivated influenza vaccine, IIV3, in Korean adults aged 18 to 60 years old. The results showed that IIV4 provided robust immunogenicity against awful vaccine strains, with seroconversion rates of at least 40% for all but the H1N1 strain. Additionally, IIV4 provided higher hemagglutination inhibition antibody titers for the additional B-lineage strain not in IIV3, Victoria, compared to IIV3. The study also found that solicited reactions and adverse events were similar between IIV4 and IIV3, and no serious adverse events or new safety signals were detected. Overall, these results confirmed the robust immunogenicity and acceptable safety of IIV4 in adults aged 18 to 60 years old, and suggest that including a second B-lineage strain can provide broader protection against B-strain influenza without affecting vaccine safety or the immunogenicity of other three vaccine strains. Thank you for watching, please click the link in the description below.