Prevalence and pattern of adverse events following COVID-19 vaccination among adult population in Sokoto metropolis, northwest, Nigeria

Background COVID-19 still poses a major public health challenge worldwide and vaccination remains one of the major interventions to control the disease. Different types of vaccines approved by the World Health Organization (WHO) are currently in use across the world to protect against the disease. This study assessed the prevalence and pattern of adverse events following immunization (AEFI) after receiving COVID-19 vaccine (the Oxford-AstraZeneca vaccine) among the adult population in Sokoto metropolis, North-west, Nigeria. Methods We conducted a cross-sectional study among 230 adults in Sokoto metropolis who received COVID-19 vaccines. Data was collected using a structured questionnaire administered via personal phone calls to respondents who were selected via a systematic sampling technique. For data analysis, IBM SPSS version 25.0 was used. Results The majority of the participants [183 (79.7%)] experienced AEFI. The most common adverse events were body weakness [157 (85%)], fever [111 (60.3%)] and headache [103 (56%)]. Up to half of the respondents that experienced AEFI said it occurred within minutes and a few hours, whereas 75 (40.8%) said it was within 2-3 days. Up to 66.3% of the adverse reactions were mild and lasted between a few hours (37.5%) and one day (31.5%); however, 15.2% of the respondents had severe reactions of which 22.7% were admitted to a health facility. The development of AEFI was linked to the presence of an underlying medical condition (p = 0.001), a previous history of AEFI (p = 0.017), and a history of drug reaction (p = 0.005). Conclusion The majority of respondents reported adverse events following vaccination with the Oxford-AstraZeneca vaccine; body weakness, fever, and headache being the most common AEFIs. History of underlying medical condition as well as a history of adverse drug reactions were predictors of the development of adverse reactions following COVID-19 vaccination. Service providers at each COVID-19 vaccination point should always take the time to explain to vaccine recipients that adverse reactions are possible; however, they should reassure them that most ARs resolve within a few hours to a few days.