Assessment of adverse events among healthcare workers following the Janssen COVID-19 vaccine in Tigray, Ethiopia

Apart from the inequality in vaccination, war zones and areas where communication is disrupted are affected by myths and misconceptions about COVID-19 vaccines, heightening vaccine hesitancy. Local data on adverse events of the vaccines and their mildness can increase confidence and acceptance of the vaccines in the respective population. In areas of conflict and communication blackouts, the perception of the vaccines by health workers is of paramount importance as public health recommendations may not reach the public. Therefore, the scientific evaluation of adverse events following COVID-19 vaccination in such areas is invaluable. This cross-sectional, facility-based study was conducted using a structured, interviewer-administered questionnaire to assess the adverse events experienced by healthcare workers who received the Janssen COVID-19 vaccine. The sample was divided proportionally to the number of vaccinated healthcare workers for the different healthcare professions, and participants were then randomly selected from each profession. Prior to data collection, a pilot test was conducted with 5% of the sample size outside the selected hospital. The study was conducted using a structured questionnaire completed by an interviewer to assess adverse events in 442 healthcare workers who had received the Janssen COVID-19 vaccine between July 11 and 25, 2022. The study period was from August 15 to September 15, 2022. A significant number of healthcare workers [366 (83.3%); 95% CI 79.5%, 86.5%] experienced at least one adverse event. Nearly 90% of participants reported that the adverse events were mild to moderate. Pain at the injection site [307 (69.5%); 95% CI 65.0%, 73.6%] and headache [247 (55.9%); 95% CI 51.2%, 60.4%] were the most common local and systemic adverse events, respectively. Two HCWs experienced anaphylactic reaction. Younger age was significantly associated with the occurrence of adverse events. We deciphered that the adverse events reported by the study participants were not different from the typically occurring vaccine-related adverse reactions, and therefore concluded that post-vaccination reactions in healthcare workers were minor. Although vaccination in Tigray is currently stalled due to the siege, responsible stakeholders should develop a mechanism to track population-wide adverse events once the vaccines start to rollout.