Impact of influenza vaccination on the risk of SARS-CoV-2 infection in a middle-aged group of people

ABSTRACT

Aims: An observational study of a retrospective cohort was performed to assess the impact of influenza vaccination (IV) on the risk of SARS-CoV-2 infection in a population of middle-aged people for 8 weeks after IV and compared with an unvaccinated group.

Patients and methods: Data from 1098 middle-aged patients (53.7 ± 4.7 years) after IV and 1205 unvaccinated patients (50.1 ± 6.8 years) were analyzed based on medical documentation. The inclusion criteria were age between 40 − 60 years and IV in the period from 1−30 September 2020. The incidence of infection with SARS-CoV-2 was confirmed by PCR and the classification of ICD-10 (U07.1).

Results and conclusions: After IV, patients had significantly fewer SARS-CoV–2 infections than the unvaccinated patients (P = .017). The hazard ratio was 0.74 (95% CI: 0.54−0.89). IV may partially reduce the risk of SARS-CoV-2 infection.

KEYWORDS:

• Vaccine
• immunotherapy
• comparative effectiveness
• influenza
• SARS-CoV-2

Acknowledgments

The authors thank Dr. M. Lodek and Dr. I. Zlotek for their cooperation and for sharing the data.

Authors’ contributions

Andrzej Bozek: concept of the project, data collection, manuscript preparation; Renata Kozłowska: data collection, data analysis; Beata Galuszka: data collection, data analysis, review of the literature and responsibility for designing the study. All authors read and approved the final manuscript; Alicja Grzanka- data recalculation, statistical analysis.

Data sharing statement

The data for this manuscript are available from the corresponding authors upon reasonable request.

Disclosure of potential conflicts of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in this manuscript.

Ethical conduct of research

This study was reviewed by the Ethics Committee (Katowice, Poland), but no special permission was needed for this project; however, written informed consent was obtained from the enrolled patients.