Absence of association between 2019‐20 influenza vaccination and COVID‐19: Results of the European I‐MOVE‐COVID‐19 primary care project, March‐August 2020

Abstract

Background Claims of influenza vaccination increasing COVID‐19 risk are circulating. Within the I‐MOVE‐COVID‐19 primary care multicentre study, we measured the association between 2019‐20 influenza vaccination and COVID‐19. Methods We conducted a multicentre test‐negative case‐control study at primary care level, in study sites in five European countries, from March to August 2020. Patients presenting with acute respiratory infection were swabbed, with demographic, 2019‐20 influenza vaccination and clinical information documented. Using logistic regression, we measured the adjusted odds ratio (aOR), adjusting for study site and age, sex, calendar time, presence of chronic conditions. The main analysis included patients swabbed ≤7 days after onset from the three countries with <15% of missing influenza vaccination. In secondary analyses, we included five countries, using multiple imputation with chained equations to account for missing data. Results We included 257 COVID‐19 cases and 1631 controls in the main analysis (three countries). The overall aOR between influenza vaccination and COVID‐19 was 0.93 (95% CI: 0.66‐1.32). The aOR was 0.92 (95% CI: 0.58‐1.46) and 0.92 (95% CI: 0.51‐1.67) among those aged 20‐59 and ≥60 years, respectively. In secondary analyses, we included 6457 cases and 69 272 controls. The imputed aOR was 0.87 (95% CI: 0.79‐0.95) among all ages and any delay between swab and symptom onset. Conclusions There was no evidence that COVID‐19 cases were more likely to be vaccinated against influenza than controls. Influenza vaccination should be encouraged among target groups for vaccination. I‐MOVE‐COVID‐19 will continue documenting influenza vaccination status in 2020‐21, in order to learn about effects of recent influenza vaccination.

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

“…The results are consistent with other studies assessing influenza vaccine and coronavirus infection risk. Our results align with a TND study at primary care sites in Europe which reported an adjusted odds ratio of 0.93 (95% CI 0.66–1.32) for influenza vaccination in COVID‐19 cases versus test‐negative controls 9 . Another TND study of data from Canadian primary care sites across seven influenza seasons prior to the pandemic reported an adjusted odds ratio of 1.04 (95% CI, 0.85–1.28) for influenza vaccination in seasonal coronavirus cases versus test‐negative controls 3 .…”

“…The test‐negative design (TND) is a robust method for estimating influenza vaccine effectiveness (VE), and yields a valid estimate of VE under most scenarios 8 . Prospective studies of influenza vaccination and coronaviruses using the TND have been reported from Europe and Canada, but not the United States 3,9 . Further, few evaluations of influenza vaccination and COVID‐19 have examined risk in children, leaving them an understudied population.…”

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.…”

Are Posterior Oropharyngeal Saliva Specimens an Acceptable Alternative to Nasopharyngeal Sampling for the Monitoring of SARS-CoV-2 in Primary-Care Settings?

“…Despite the limitations of the data collected, the main findings of this study showed that saliva samples could be an acceptable alternative to NPS for the virological surveillance of SARS-CoV-2 in mildly symptomatic patients with ARI in primary care. Systems for data collection on patients with ARI have been affected at a European level by the COVID-19 pandemic, leading to some difficulties in providing robust 2019–2020 estimations of influenza vaccination in primary care [ 30 ]. These findings suggest that the circulation of respiratory pathogens other than SARS-CoV-2 could be monitored by using saliva samples.…”