Abstract
Background The most important factor in combating the coronavirus disease 2019 (COVID-19) pandemic was the provision of safe and effective vaccines. The acceptance of vaccines is impacted by several variables, including beliefs about the vaccine's safety and adverse effects. Vaccine side effects can vary depending on the type, but they are often moderate, localized, transient, and self-limiting. Therefore, this study aimed to assess the prevalence of side effects experienced after receiving the Sinovac vaccine by participants hypertensive and non-hypertensive participants. Methodology This was a cross-sectional, multicenter study that was performed using non-probability sampling. The study duration was six months from May 1, 2022, to October 31, 2022. The study involved 600 individuals who had either received the first or second dose of the Sinovac vaccine. For categorical data, frequencies and percentages were documented. The chi-square test was applied to determine the association between local and systemic side effects among hypertensive and non-hypertensive participants. Results The study findings showed that out of 600 participants, there were 187 (62.3%) males and 113 (37.7%) females with hypertension, and 222 (74.0%) males and 78 (26.0%) females without hypertension, with a significant association (p = 0.002). Following the first dose of the Sinovac vaccine, fever was the most commonly reported side effect in 153 (51.0%) hypertensive participants and 62 (20.7%) non-hypertensive participants, with a significant association (p < 0.001). Similarly, following the second dose of the Sinovac vaccine, fever was the most commonly reported side effect in 108 (36.0%) hypertensive participants and 57 (19.0%) non-hypertensive participants, with a significant association (p < 0.001). Conclusions This study concluded that the presence of hypertension significantly increased the manifestations of local and systemic side effects compared with non-hypertensive participants. Moreover, fever, pain, and swelling at the injection site were the most commonly reported side effects after receiving the first and second doses of the Sinovac vaccine.