ADVERSE EVENTS FOLLOWING IMMUNISATION WITH THE OXFORD-ASTRAZENECA COVID-19 VACCINE AMONG HEALTHCARE PROFESSIONALS IN NIGERIA

Abstract

Background: The Oxford-AstraZeneca COVID-19 vaccine was deployed in Nigeria on the 5^th of March, 2021 with a goal of vaccinating 70% of the population by 2022. This goal is however being threatened by widespread vaccine hesitancy fueled by skepticism around vaccine safety. This study leverages on the clinical acumen of healthcare professionals to evaluate the occurrence of adverse events following immunization to the vaccine in tertiary hospitals in Nigeria.

Methods: It was a retrospective study conducted using a self-administered questionnaire from 25^th May to 17^th July 2021 in 4 tertiary hospitals across the north central zone of Nigeria. Participants were asked to report the type, intensity and duration of symptoms experienced following Oxford-AstraZeneca COVID-19 vaccine administration. Data was analyzed using SPSS version 22.0.

Results: Of the 295 vaccine recipients who took part in this study, around 71.1% of them reported experiencing at least one symptom with injection site pain (31.3%), fever (25.4%), tiredness (23.6%) and headache (22.9%) being the most commonly reported adverse events. Majority of the reported symptoms began within a day of vaccination; most had no impact on routine daily activities and almost two-thirds had resolved two days after their commencement. The frequency of reported symptoms was higher in: the younger (<40 years) age group, those who had taken two doses, and participants with a history of adverse reaction to a medicine/vaccine. These findings were consistent with those of clinical trials and similar studies in other regions.

Conclusion: As with other vaccines, some adverse events follow the administration of Oxford-AstraZeneca COVID-19 vaccine. Most of these events are short term, tolerable and similar to those reported in other parts of the world. Vaccine recipients should be informed about potential symptoms, how to handle them, and when and where to seek additional guidance if necessary. The findings in this study should help counter vaccine hesitancy by enhancing public confidence in Oxford-AstraZeneca COVID-19 vaccine safety.