Influenza Vaccine Effectiveness in Mainland China: A Systematic Review and Meta-Analysis

Abstract

Influenza endangers human health but can be prevented in part by vaccination. Assessing influenza vaccine effectiveness (VE) provides scientific evidence for developing influenza vaccination policy. We conducted a systematic review and meta-analysis of studies that evaluated influenza VE in mainland China. We searched six relevant databases as of 30 August 2019 to identify studies and used Review Manager 5.3 software to analyze the included studies. The Newcastle–Ottawa scale was used to assess the risk of publication bias. We identified 1408 publications, and after removing duplicates and screening full texts, we included 21 studies in the analyses. Studies were conducted in Beijing, Guangzhou, Suzhou, and Zhejiang province from the 2010/11 influenza season through the 2017/18 influenza season. Overall influenza VE for laboratory confirmed influenza was 36% (95% CI: 25–46%). In the subgroup analysis, VE was 45% (95% CI: 18–64%) for children 6–35 months who received one dose of influenza vaccine, and 57% (95% CI: 50–64%) who received two doses. VE was 47% (95% CI: 39–54%) for children 6 months to 8 years, and 18% (95% CI: 0–33%) for adults ≥60 years. For inpatients, VE was 21% (95% CI: −11–44%). We conclude that influenza vaccines that were used in mainland China had a moderate effectiveness, with VE being higher among children than the elderly. Influenza VE should be continuously monitored in mainland China to provide evidence for policy making and improving uptake of the influenza vaccine.

Meta‐analysis of whether influenza vaccination attenuates symptom severity in vaccinated influenza patients

“…Vaccine effectiveness (VE) is affected by many factors, including the matching between influenza vaccine strain and epidemic strain and host factors, such as age, health status, and pre‐existing immunity (Mastalerz‐Migas et al., 2013). VE has been found to be 47% in children, 18% in the elderly, 45% in asthma patients, 13% in diabetes patients, and 59% in healthy adults (Osterholm et al., 2012; Remschmidt et al., 2015; Yang et al., 2021).…”

Influenza vaccine effectiveness against hospital-attended influenza infection in 2023/24 season in Hangzhou, China

“…In addition, the influenza positivity 16 rates in the ILI cases in these three studies ranged from 20% to 27% [23][24][25], much lower than the 36% influenza positivity rate in this study. This may suggest a relative higher VE during massive influenza epidemics, since the overall influenza VE was only 36% from a meta-analysis of the influenza VE before the pandemic in China [26].…”

Parental Preferences of Influenza Vaccination for Children in China: A National Survey with a Discrete Choice Experiment

“…DCE studies are widely used in vaccine policy analysis to predict the probability of vaccine uptake with different combinations of vaccine attributes [ 25 ], which provides evidence for policy makers to make decisions regarding immunization programs [ 6 , 17 , 21 , 22 ]. In China, the effectiveness of influenza vaccination varies according to season and is estimated to be 18–57%, with the highest rate among children aged 6–35 months who receive two doses [ 34 ]. In our study, we predicted that the influenza vaccine uptake rate would increase 19.31–41.85% when vaccine effectiveness improved from 30% to 50–80%.…”