(1) Background: Vaccination is the most effective intervention to control seasonal influenza morbidity and mortality. The present study aimed to determine the influenza vaccination coverage in the Military Health Corps personnel in the 2020−2021 season, as well as the time trend and the possible influence of the pandemic on coverage, in order to study the reasons that led to the non-vaccination of health professionals and to analyze adverse drug reactions (ADRs). (2) Methods: A descriptive, cross-sectional study was conducted from February to May 2021. All FAS CMS personnel were included. A self-administered questionnaire was sent by e-mail to the selected personnel. (3) Results: Vaccination coverage in the 2016−2017 season was 15.8% (n = 276), in the 2019−2020 season it was 17.41% (n = 424), and in the 2020−2021 season it was 24.22% (n = 590). The percentage of vaccinated men was higher than the percentage of women. In 2019 and 2020 the most vaccinated group was 31−40 years old. Lieutenants had the highest vaccination uptake in 2019 and 2020. The personnel with the highest uptake of vaccines were those in the specialty of nursing in each of 2016, 2019 and 2020, with >30 years of time worked in 2016. In terms of factors leading to refusal of vaccination, the most reported was “not considered a risk group” (23.0%), and the least reported was “avoidance of vaccine administration” (2.2%). Eighty individuals presented adverse reactions after vaccine administration (9.6%). (4) Conclusions: The rate of influenza vaccination among healthcare professionals was lower during the 2020 season compared to the previous season, but was expected to increase in the upcoming 2021 season.
Keywords: adverse reactions; influenza vaccines; military personnel; vaccination coverage.