Quadrivalent influenza vaccine (Sinovac Biotech) for seasonal influenza prophylaxis

ABSTRACT

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 µg 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:

• Quadrivalent influenza vaccine
• inactivated influenza vaccine
• safety
• immunogenicity
• seasonal influenza

Declaration of interest

Y-S Hu and G Zeng are employees of Sinovac Biotech Co., LTD. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose

Author contributions

All authors contributed significantly to the manuscript. Y-Y Tao contributed to the data collection, data analysis and wrote the draft of the manuscript. Y-M Hu prepared this manuscript for publication. Y-S Hu, G Zeng and F-C Zhu took responsibility for the integrity of the data analysis, and J-X Li and F-C Zhu reviewed the manuscript. All authors read and approved the final manuscript.

Additional information

Funding

The manuscript was funded by the National Major Scientific and Technological Special Project of China (2018ZX09734004).