Adverse events following introduction of the ChAdOx1 nCoV-19 vaccine in Somalia in 2021: findings from a fragile setting and implications for the future.

Background: Vaccination against coronavirus disease 2019 (COVID-19) began in Somalia on 16 March 2021 with the Covishield (ChAdOx1 nCoV-19) vaccine. However, by the end of 2021, only a small percentage of the population had been fully vaccinated. As side effects play an important role in determining public confidence in vaccines and their uptake, this study aimed to examine reported adverse events following immunization (AEFIs) of vaccine recipients.

Methods: This cross-sectional-survey-based study was conducted between March and October 2021 in Somalia. Vaccine recipients who were eligible to receive the first dose of the Covishield vaccine in the first phase of COVID-19 vaccination were eligible for study inclusion. <0.05 was considered to indicate significance.

Results: Of the 149,985 respondents who had received the first dose of the Covishield vaccine, 378 reported side effects. This represented a reported AEFI rate of 2.5 per 1000 population. Amongst those who reported adverse events, males (2.8 per 1000; <0.001), respondents aged 35-49 years (3.3 per 1000; =0.001) and teachers (3.5 per 1000; =0.000) had higher rates of adverse events compared with females, other age groups and other occupations. Amongst population settlement types, a higher rate of AEFIs was observed amongst refugees (23.9 per 1000; =0.000) and internally displaced populations (19 per 1000; =0.000). Nearly half of the vaccine recipients who reported side effects (48%) reported one local symptom, and most symptoms were mild in nature. The probability of having acute and severe side effects was found to be 66% lower among males compared with females [odds ratio (OR) 0.44, 95% confidence interval (CI) 0.26-0.73; =0.002]. Respondents aged >60 years (OR 1.52, 95% CI 0.64-3.62; =0.34) were more likely to develop acute and severe AEFIs. None of the study population reported any severe life-threatening symptoms or death.

Conclusion: Some variables (sex, profession, age) put recipients at higher odds of acute and severe AEFIs, but the Covishield vaccine generally produced mild side effects in a small proportion of the vaccinated population in Somalia. This study confirms that COVID-19 vaccines are safe, and their benefits clearly outweigh any associated risk.