Effect of intervention on influenza vaccination during 2021 – 2022 influenza season among hospital professionals in a district of Shenzhen city

  Objective  To evaluate the effect of an intervention with a required non-mandatory vaccination rate on improving influenza vaccination among healthcare workers in 2021 – 2022 influenza season.

  Methods  We conducted a non-randomized community intervention trial on influenza vaccination among healthcare workers in 7 hospitals in Nanshan district of Shenzhen city during an influenza season from October 2021 to April 2022. Free on-site influenza vaccination and prompt publicity for the vaccination were carried out among all the participants; compared to the 2 139 control participants in 3 hospitals, an additional dissemination about the expected non-mandatory vaccination rate of 80% and 60% for the staff working in departments assessed as at high- and low-risk of influenza infection was implemented among 4 599 participants in 4 hospitals of the intervention group. Pearson′s chi-square test for adjusted ratio estimators was used to test the baseline and post-intervention vaccination rates for the intervention and control group.

  Results  Over the influenza season for the participants working in high-risk departments, the influenza vaccination rate was 62.67% and 23.71% in the intervention and the control group, with a significant absolute rate difference (ARD) of 38.96% (95% confidence interval: 14.17% – 63.75%) between the two groups (P < 0.05); for the participants of low-risk departments, the influenza vaccination rate was 34.57% and 22.96% in the intervention and the control group (P > 0.05); for all the participants, the influenza vaccination rate was 43.90% and 23.19% in the intervention and in the control group (P > 0.05). The intervention of dissemination about the expected vaccination rate showed a significant impact upon the influenza vaccination rate for the participants working in high-risk departments but not for those in low-risk departments.

  Conclusion  Under the premise of without both reward and punishment for having influenza vaccination, the dissemination of a high expected non-mandatory vaccination rate may increase the influenza vaccination rate among healthcare workers intervened.