Selection bias may explain the relationship between coronavirus diagnosis and the odds of prior influenza vaccination.

Abstract

A potential study design then may he a classical observational cohort study;wherein, a sample of individuals presenting with influenza-like illness (ILI) are separated into groups by exposure to influenza vaccine and influenza infection is then ascertained through laboratory confirmation A study by Wolff [41, using 2017-2018 influenza season data, employed such a test-negative design to assess influenza VE among United States Department of Defense personnel Wolff analyzed for influenza vaccine exposure status among study subjects presenting with ILI Ivtween rhose testing positive for combined non influenza respiratory virus (NIRV) influenza-positive cases excluded against those testing negative for influenza and other NIRVs tested (no respiratory virus detected) This analysis revealed a nonsignificant association between influenza vaccination and development of grouped NIRVs (adjusted odds ratio: 0 97, 95% confidence interval: 0 86-1 09) Wolff found a greater odds of influenza vaccination among those diagnosed with coronavi ruses, suggestive of a greater risk of coronavirus infection among those vaccinated against influenza (unadjusted odds ratio: 1 36, 95% confidence interval: