Prevalence and factors associated with Oxford/ AstraZeneca vaccine adverse effects; a cross-sectional study in Tororo, eastern Uganda.

Abstract

Background: Vaccines are the most effective strategy against COVID-19 pandemic but have faced roll out challenges partly due to fear of potential side effects. Literature review reveals that socio demographic and other personal factors influence side effect experiences. Uganda rolled out COVID -19 vaccination in April 2021 with Oxford /AstraZeneca vaccine targeting Health workers, teachers, and Security personnel, elderly persons above 50 years and adults above 18 with underlying conditions. This study was conducted to determine prevalence, profiles and predictors of Oxford/AstraZeneca vaccine side effects among the vaccine recipients in Tororo district. Methods: A cross sectional analytic study was conducted in Tororo using secondary data from the COVID -19 registers from all the five vaccination sites extracted using a data extraction tool. Telephone interviews with 2204 participants using a pretested structured questionnaire were done to collect quantitative data on the side effects of Oxford/AstraZeneca vaccine. Stata version 13 was used for analysis. Bivariate and multivariate analyses were done to infer associations between side effects of Oxford/AstraZeneca vaccine and potential predictor variables. Adjusted odds ratios with their 95% confidence intervals were calculated and interpreted. Results: A total of 603/2204(27.4%) of the participants experienced side effects. Of these 102/2204 (4.6%) had only local side effects while 298/2204 (13.5%) experienced only systemic side effects. Therefore 305/603 (50.6%) experienced local side effects while 501/603 (83.1%) experienced systemic side effects. A total of 247/305 (80.9%) of the local side effects were pain at the injection site. More than half 218/305(71.5%) of the participants experienced headache, 203/305 (66.6%) of the participants experienced tiredness and 134/305 (43.9%) experienced fever. A total of 268/424 (63.21 %) participants experienced side effects only after the first vaccine dose, 44/424 (10.38%) experienced side effects only after the second dose and 112/424 (26.42%) experienced side effects after both doses. Six participants declined second dose because of side effects after the first dose. A total of 61/603(10.1%) of the participants sought medical attention from a health facility following side effects of AstraZeneca. Average duration of side effects was 2-3 days. Seven deaths were reported among the 2204 participants called up however they were likely not directly related to the side effects the Oxford/AstraZeneca vaccine. Previous infection with COVID-19 (AOR: 4.3, 95% CI: 2.7-7.0, p = < 0.001), and being female (AOR: 1.3, 95% CI: 1.1-1.6, p = 0.004) were positively associated with side effects to Oxford/AstraZeneca vaccine while being a security officer (AOR: 0.4, 95% CI: 0.2-0.6, p = <0.001) was a protective factor as it was less associated with side effects of Oxford/AstraZeneca. Conclusion and recommendations Following vaccination with Oxford/AstraZeneca vaccine participants reported side effects that were majorly local and systemic. Most of the side effects were minor events that were self -limiting. We recommend massive campaigns to disseminate correct information about potential side effects of Oxford/ AstraZeneca vaccine and strengthening the passive surveillance for adverse events following vaccination.