Al Bahrani, SalmaAlbarrak, AliAlghamdi, Othman AliAlghamdi, Mesfer AbdullahHakami, Fatimah H.Al Abaadi, Asmaa K.Alkhrashi, Sausan A.Alghamdi, Mansour Y.Almershad, Meshael M.Alenazi, Mansour MoklifEl Gezery, Mohamed HanyJebakumar, Arulanantham ZechariahAl-Tawfiq, Jaffar A.2021-11-102021-11-102021-09Al Bahrani, S., Albarrak, A., Alghamdi, O. A., Alghamdi, M. A., Hakami, F. H., Al Abaadi, A. K., Alkhrashi, S. A., Alghamdi, M. Y., Almershad, M. M., Alenazi, M. M., El Gezery, M. H., Jebakumar, A. Z., & Al-Tawfiq, J. A. (2021). Safety and Reactogenicity of the ChAdOx1 (AZD1222) COVID-19 Vaccine in Saudi Arabia. International Journal of Infectious Diseases, 110, 359–362. https://doi.org/10.1016/j.ijid.2021.07.05212019712https://hdl.handle.net/1805/26975Introduction The Kingdom of Saudi Arabia was one of the first countries to implement a COVID-19 vaccination program. This study estimated the safety and reactogenicity of the ChAdOx1-S vaccine after the first dose administered to adults. Methods This cross-sectional study included 1592 randomly selected vaccinees from April to May 2021. A questionnaire was delivered to the vaccinees via phone calls 7 and 21 days after the first vaccine dose. Results Of the 1592 vaccinees who had the first dose, the mean age was 37.4 (± 9.6) years and 81% were males. Of all the vaccinees, 553 (34.7%) reported an adverse reaction on the first telephone call. The most common symptoms were: pain at the site of injection (485, 30.5%), musculoskeletal symptoms (438, 27.5%), skin rash (307, 19.2%), gastrointestinal symptoms (379, 23.8%) and fever (498, 31.3%). Men were more likely to report fever (76.9% vs. 23.1%; P = 0.005), skin rash (81.1% vs. 18.9%, P = 0.005) and pain at the injection site (77.3% vs. 22.7%, P < 0.0001). Post-vaccine COVID-19 infection was 0.5% and there were no hospitalizations. Conclusion This study observed no major side effects of the ChAdOx1-S vaccine and no reported breakthrough infection during the observation period.en-USAttribution-NonCommercial-NoDerivatives 4.0 InternationalChAdOx1-SCOVID-19 vaccineSARS-CoV-2Oxford-AstraZeneca vaccineArticle