Immediate adverse events following immunization (AEFI) in drive-through COVID-19 vaccination campaign in Yogyakarta, Indonesia: A cross-sectional study

Background & objectives The COVID-19 pandemic has led to unprecedented global immunization efforts, with drive-through vaccination campaigns established to expedite and ensure safe coverage. However, research on immediate adverse events following immunization (AEFI) in these settings is limited. This study aims to evaluate the frequency and characteristics of immediate AEFI during drive-through COVID-19 vaccination campaigns in Yogyakarta, Indonesia, using the Sinovac/CoronaVac vaccine Methods This cross-sectional study utilized secondary data from the local vaccine registry managed by the Faculty of Medicine, Public Health, and Nursing, Universitas Gadjah Mada, Indonesia, from July 27 to September 6, 2021. Participants included individuals aged over 11 yr without underlying medical conditions such as diabetes, hypertension, cancer, or asthma. Key characteristics recorded were age, gender, and AEFI. Results Out of 27,459 registrants, only 20,817 were eligible and received a dose. The median participant age was 20 yr (IQR 10); 47 per cent were male (9,712) and 53 per cent female (11,105). The highest vaccination day was September 6, 2021, with 3,883 doses (18%). Among the 79 participants who experienced AEFI [0.38%; 95% Confidence Interval (CI): 0.30-0.47], the median age was 19 yr (IQR 8); 41 per cent were male (34) and 59 per cent female (48). Systemic adverse events (92%) were more common than local events (6.3%), with dizziness (77.2%) being most prevalent. Interpretation & conclusions The findings of this study suggest that immediate AEFI occurred rarely in the drive-through vaccination setting, indicating that this method appears safe and efficient for COVID-19 vaccinations, particularly in the context of immediate AEFI. Most adverse events were mild, underscoring the importance of preparedness and close monitoring in drive-through vaccination campaign sites to ensure patient safety and enhance vaccine confidence.