Prevalence and Predictors of Adverse Reactions to COVID-19 AstraZeneca Vaccine among Healthcare Staff of General Hospital Ilorin, North-Central, Nigeria

Background: Vaccines are crucial for an effective global pandemic response. Despite the proven efficacy and safety of the COVID-19 AstraZeneca vaccine by the World Health Organization, some adverse effects have been reported.

Aim: This was to determine the prevalence of adverse reactions to COVID-19 vaccine among the healthcare workers, to assess the time of onset of symptoms after vaccination, to determine the total duration of persistent of symptoms after vaccination among respondents and to determine the socio-demographic and clinical predictors of adverse reactions among the participants.

Materials and Method: This study was a hospital-based descriptive cross-sectional study, and it was conducted at the General Hospital Ilorin (GHI), Kwara State. The study population consists of 121 health workers at GHI who received the first dose of COVID-19 vaccine. Interviewers’ administered questionnaires were used to obtain socio-demographic and some clinical information from the participants. Clinical measurements were done using weighing scale, stadiometer, stethoscope, and sphygmomanometer.

Results: The mean age of the participants was 39.5±8.9. The most commonly reported adverse drug reactions (ADRs) among the participants were site tenderness (51.2%), site pain (51.2%), fatigue (25.6%), and myalgia (24%). There was no report of blood clotting problems among them (0%). The majority of the ADRs started within 30 minutes to about 24 hours after the respondents received their COVID-19 vaccine jabs except for arthralgia which developed after 24 hours in the majority of the respondents who had it (61.5%). Most of the ADRs resolved completely within 24 hours to 72 hours except for chills that lasted for less than 24 hours among the majority of the participants who had it (53.3%), and also myalgia that lasted for more than 72 hours among the highest percentage of participants who reported having it (41.4%). The results of the multiple logistic regression analysis revealed no statistically significant predictors for the reactions (All reported P-values for all the regression coefficients were greater than 0.05).

Conclusion: This study reported the prevalence, time of onset and duration of ARs to the first dose of AstraZeneca vaccine among health workers in Ilorin. The prevalence and pattern of the ARs reported is similar to those from other countries and continents. No report of severe anaphylactic reactions or blood clotting problems among the respondents. The time of onset and duration of most ARs were between 30 minutes to 24 hours, and less than 3 days respectively. The study also reported that no socio-demographic or clinical factors studied could significantly predict the occurrence of ARs among the participants.