Evaluation of Prevalence of Side-Effects Associated with Booster Dose of mRNA-Based COVID-19 Vaccine Among Healthcare Workers in Eastern Province, Saudi Arabia: A Descriptive Cross-Sectional Study

Background: The purpose of this study was to examine the mild and moderate side-effects experienced by the healthcare workers (HCWs) in the Eastern Province of Saudi Arabia after receiving the booster dose of the Pfizer-BioNTech/BNT162b2 COVID- 19 vaccine. Methods: We directed a descriptive cross-sectional study among adults living in the Eastern Province of Saudi Arabia. A survey link was distributed through WhatsApp, SMS, or e-mail to HCWs. Participants' general and demographic information were also collected, as well as information about any local and systemic side-effects reported following vaccination. Results: The results of this study showed that 81.84% (401/490) of the HCWs who contributed to this study reported the minimum COVID-19 post-vaccination side-effect. Body pain (89%) and pain at the site of injection (88.73%) were the most frequent frequently reported side-effects, followed by headache (28.68%), joint or bone pain (27.18%), muscle pain (26.43%), nausea or vomiting (21.2%), fever (18.95%), skin rashes (10.22%). History of chronic diseases had a 0.44-fold increased risk of side- effects compared to no history of chronic diseases HCWs (adjusted odds ratio (aOR) = 0.44; 95% CI = 0.224, 0.880), and significant association of occupation with side-effects was also 1.61-fold increased risk compared to nonmedical ((aOR) = 1.61; 95% CI = 1.037, 2.513). Conclusion: According to this study, the Pfizer-BioNTech/BNT162b2 COVID-19 vaccine was safe when given to Saudi Arabian HCWs. All reported side-effects were mild to moderate. The outcomes indicated that most participants had body pain and pain at the site of injection and fatigue is among the least reported side-effect post-booster dose. Healthcare was highly connected with more reporting of side-effects. Keywords: COVID-19, vaccine, side-effects, healthcare workers, Eastern Province, Saudi Arabia