Safety of recombinant quadrivalent influenza vaccine compared to inactivated influenza vaccine in Chinese adults: An observational study

Abstract

Background: Recombinant influenza vaccine (RIV) has been in use in US adults since 2013. This study evaluated the safety of quadrivalent recombinant influenza vaccine (RIV4, Flublok® Quadrivalent, Sanofi Pasteur) compared with standard-dose quadrivalent inactivated influenza vaccine (SD-IIV4) in self-identified Chinese adults at Kaiser Permanente Northern California (KPNC).

Methods: This study evaluated adults aged 18-64 years within KPNC during the 2018-2019 influenza season who self-identified as Chinese (NCT03694392). We compared the rates of prespecified diagnoses of interest in the emergency department and inpatient settings as done in prior influenza studies, for three risk intervals: 0-2 days, 0-13 days, and 0-41 days following influenza vaccination, as well as number of deaths within 0-180 days after vaccination. We estimated the odds ratios (ORs) and 95% confidence intervals using logistic regression adjusted for sex, age group, presence of comorbidities, and same-day concomitant vaccination.

Results: Comparing 15,574 adults who received RIV4 with 27,110 who received SD-IIV4, there was no statistically significant difference in the prespecified diagnoses of interest and deaths between the 2 groups. There were 35 deaths total, none of which were considered to be related to influenza vaccination.

Conclusions: This study did not identify any safety concerns regarding RIV4 use among 18-64-year-olds who self-identified as Chinese. This study supports the safety of RIV4 vaccine in this population.

Keywords: Influenza; Vaccines.

Conflict of interest statement

Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.