Risk of symptomatic severe acute respiratory syndrome coronavirus 2 infection not associated with influenza vaccination in the 2019–2020 season

Abstract

The association of influenza vaccine and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was assessed by test-negative design using data collected for a study of outpatient COVID-19-like illness with onset dates from June to September 2020. Multivariable logistic regression models examined the association between receipt of 2019-2020 influenza vaccine and PCR-confirmed SARS-CoV-2 with adjustment for potential confounders. Receipt of influenza vaccine during the 2019-2020 influenza season was not associated with increased odds of SARS-CoV-2 infection in adults (aOR 0.83, 95% CI 0.63 to 1.10) or children (aOR 0.92, 95% CI 0.47 to 1.80).

The Association Between Previous Influenza Vaccination and COVID-19 Infection Risk and Severity: A Systematic Review and Meta-analysis

“…A total of 3,887 studies met the initial search criteria. After 3 rounds of screening, a total of 23 studies 3,5,15,[27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46] met the inclusion criteria. The detailed process of literature screening is shown in Figure 1.…”

“…In total, this study extracted unadjusted and adjusted RRs, HRs, or ORs from the original data for 23 studies for synthesis. Of these, 16 studies 3,[27][28][29][30][31][32][33][34][35][36][37][38][39][40][41] examined the association between influenza vaccination and the risk of COVID-19 infection, 7 studies 28,30,34,40,[42][43][44] examined the association between influenza vaccination and the risk of hospitalization in COVID-19 patients, 5 studies 15,34,[43][44][45] assessed the association between influenza vaccination and the risk of ICU admission in COVID-19 patients, and 6 studies 5,40,42,43,45,46 explored the association between influenza vaccination and the risk of death in COVID-19 patients. The results showed that influenza vaccination was associated with a reduced risk of COVID-19 infection (RR=0.83, 95% CI=0.76, 0.90, I 2 =80.8%).…”

“…The higher heterogeneity of unadjusted correlates may have amplified the protective effect of influenza vaccine. However, certain groups, such as healthcare workers, are at significantly higher risk of exposure to SARS-CoV-2 than other workers, so healthcare workers are strongly recommended to receive influenza vaccination to reduce hospitalization and aid in the differential diagnosis with COVID-19, 38 especially in areas where the COVID-19 vaccine supply is limited.…”

Association between influenza vaccination and SARS-CoV-2 infection and its outcomes: systematic review and meta-analysis

“…Of the 92 full-text articles identified, 58 were excluded because they did not meet the inclusion criteria, and two others were obtained from the references. The remaining 36 articles reported on 55,996,841 subjects outcomes were included in this analysis [21–56] . None of the participants had received COVID-19 vaccination during the study period.…”

Influenza and Pneumococcal Vaccination and the Risk of COVID-19: A Systematic Review and Meta-Analysis

“…The following supporting information can be downloaded at: , Table S1. Baseline characteristics of the 21 publications, involving 22 studies that assessed the association between influenza vaccination and SARS-CoV-2 infection [ 15 , 29 , 31 , 32 , 33 , 36 , 37 , 38 , 40 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 60 ]. Table S2.…”