Adverse events associated with AstraZeneca COVID-19 vaccine among adults in Greater Kampala, Uganda: a cross-sectional study.

Background: Uganda started AstraZeneca COVID-19 vaccination in March 2021 but information about adverse events is limited. We assessed adverse events following AstraZeneca vaccination among adults in Greater Kampala, Uganda. Methods: In this cross-sectional study, we systematically sampled persons who had received ≥1 dose of the AstraZeneca vaccine and collected data between March and April 2021 through telephone interviews. We defined adverse events as any untoward medical occurrence after vaccination and serious adverse events as any event leading to hospitalization, persistent disability >28 days, death, or congenital anomaly. Results: Of 374 participants aged 20-85 years, the prevalence of adverse events was 76.5%. Common adverse events included injection site redness and hadache; no serious adverse event was reported. Participants aged 20-29 years (Adjusted odds ratio (AOR) 4.58; 95% confidence interval (CI): 1.92-10.95), 30-39 years (AOR 3.69; 95% CI: 1.81-7.51) and 40-49 years (AOR 2.78; 95% CI 1.26-4.90) were more likely to develop adverse events compared to those aged ≥50 years. Conclusion: Adverse events are prevalent, largely among those aged <50 years; serious adverse events are rare. Persons aged <50 years should be targeted for surveillance of adverse events alongside appropriate health education and counselling.