<p>Khomas region recorded 55244 COVID-19 cases (32.6%) and 910 (22.4%) deaths. The rapid increase in COVID-19 cases prompted the development of COVID-19 vaccines. The introduction of COVID-19 vaccines resulted in adverse effects following immunization (AEFIs). AEFIs are an indication that the vaccines are working. If not addressed adequately, AEFIs can erode trust in vaccines, affecting immunization coverage and disease incidence. A standardized case investigation form was used to report AEFIs. The objective of this secondary data analysis was to identify the age groups, sex, and severity of AEFIs in Khomas region between March 2021 and July 2022.</p>