Background: Vaccination is a key strategy to reduce infectious disease incidence and COVID-19 severity. Monitoring vaccine safety is essential to identify Adverse Reactions (ARs) and ensure public confidence.
Objective: To evaluate adverse reactions following COVID-19 vaccination at the Military Polyclinic of Rome “Celio” between 2020 and 2023, analyzing variables such as sex, age, vaccine type, and dose number, and comparing results with national (AIFA) and European (EMA) data.
Methods: A retrospective observational study was conducted on 41,276 doses administered across five vaccine types (Pfizer, Moderna, AstraZeneca, Johnson & Johnson, Novavax). ARs were classified by severity and system involved. Statistical analyses, including Chi-square and Fisher’s Exact Test, assessed correlations by age, sex, dose, and vaccine type.
Results: Total ARs: 41 (0.1% of doses); 92.7% non-severe, 7.3% severe.
Most ARs involved musculoskeletal (29.2%) and immune (26.8%) systems.
Female subjects experienced more ARs (66%) than males (34%).
ARs were most frequent after the first dose, decreasing with subsequent doses.
By vaccine type, AstraZeneca showed the highest relative rate of ARs (0.41%), followed by Moderna (0.09%) and Pfizer (0.05%).
Severe ARs were rare, predominantly in the 30–49 age group.
Local reporting rates (0.1%) aligned closely with national data (0.097%).
Conclusions: COVID-19 vaccines administered at the Military Polyclinic demonstrated a high safety profile. Severe adverse events were rare, nonsevere reactions predominated, and findings were consistent with national and European surveillance data. The benefits of vaccination in preventing severe disease, hospitalization, and death significantly outweigh the risks.