Expert Rev Vaccines

. 2021 Jan 12.
doi: 10.1080/14760584.2021.1875823. Online ahead of print.
Quadrivalent Influenza Vaccine (Sinovac Biotech) for seasonal influenza prophylaxis

Yan-Yang Tao 1 , Jing-Xin Li 2 , Yue-Mei Hu 2 , Yuan-Sheng Hu 3 , Gang Zeng 3 , Feng-Cai Zhu 1 2 4



Introduction: Quadrivalent Influenza Vaccine (Sinovac Biotech) is a quadrivalent split-virion inactivated influenza vaccine approved in China in June 2020 for individuals ≥3 years of age. It contains 15 g hemagglutinin per strain including A/H1N1, A/H3N2, B/Victoria, and B/Yamagata, which could potentially improve protection against influenza B viruses.
Areas covered: In this review, we summarize the development of quadrivalent influenza vaccines in China and foreign countries, and assess the immunogenicity and safety from the phase I and III clinical trials of Quadrivalent Influenza Vaccine in individuals ≥3 years of age. We also discuss the potential application of Quadrivalent Influenza Vaccine in young children 6-35 months of age according to the results of the phase III trial.
Expert commentary: The immunogenicity and safety profiles of Quadrivalent Influenza Vaccine containing two A and two B strains were comparable to the trivalent vaccines for the shared strains. The addition of a second B strain to the trivalent vaccine could induce superior immune responses for the alternate B strain. Since the two B strains co-circulated worldwide, the introduction of quadrivalent influenza vaccines has been expected to be a cost-effective strategy.

Keywords: Immunogenicity; Inactivated influenza vaccine; Quadrivalent influenza vaccine; Safety; Seasonal influenza.