Effectiveness of seasonal influenza vaccine against severe acute respiratory infections

Abstract

Objective To estimate the vaccine effectiveness (VE) in preventing influenza associated severe acute respiratory infection (SARI) in 2016-2017 influenza season. Methods Data were collected from SARI surveillance. The case control study design was applied to calculate odds ratios (ORs) of vaccination among influenza positive and negative cases. Results During 2016-2017 influenza season, overall adjusted VE against influenza associated SARI was 45.1% (95%CI: 6.7 - 67.7). The VE against influenza A(H1N1) pdm09 was 71.8% (95%CI: -20.1 - 93.4%) and the VE against influenza A(H3N2) was 38.0% (95%CI: -10.7 - 65.3). For patients vaccinated only in the current season, the VE was 60.2% (95%CI: -35.8 - 88.4). Conclusions The seasonal influenza vaccine of 2016-2017 influenza season showed good vaccine effectiveness against influenza associated SARI. It is recommended that vunerable population of SARI should receive influenza vaccination every year. Key words: Influenza; Vaccine; Vaccine effectiveness