Immunogenicity and safety of an intramuscular split-virion quadrivalent inactivated influenza vaccine in individuals aged ≥ 6 months in India

ABSTRACTA quadrivalent split-virion inactivated influenza vaccine (IIV4; Fluzone® Quadrivalent, Sanofi Pasteur) has been available in the US since 2013 for individuals aged ≥ 6 months. Here, we describe the results of an open-label, multicenter trial (WHO Universal Trial Number U1111-1143–8370) evaluating the immunogenicity and safety of IIV4 in Indian children aged 6–35 months and 3–8 years, adolescents aged 9–17 years, and adults aged ≥ 18 years (n = 100 per group). Post-vaccination hemagglutination inhibition titers for all strains in all age groups were ≥ 8 fold higher than at baseline (range, 8–51). At least 70% of participants in all age groups seroconverted or had a significant increase in titer for each strain. The most common solicited reactions were injection-site pain and tenderness, plus fever in participants 6–23 months and myalgia in older children and adolescents. All injection-site reactions and most systemic reactions were grade 1 or 2 and resolved within 3 days. Only three vaccine-relate...