RESUMEN
BACKGROUND: The prevalence of vaccine side effects plays an important role in public perception about vaccination programs. This study was designed to investigate the side effects of the first dose of COVID-19 vaccine; Sputnik-V, AZD-1222, and Covaxin. METHODS: A study was performed to evaluate the side effects of these vaccine among 503 health care workers in Birjand (Iran). Our study used the questionnaire consisted of 4 main categories including demographic data, previous COVID-19 infection, vaccine information, and local and systemic side effects of vaccines. RESULTS: 81.9%, 88.8%, and 92.9% of people who have been vaccinated with Sputnik-V, AZD1222, and Covaxin vaccines, respectively, have reported at least one side effect. The prevalence of systemic side effects in AZD-1222 vaccine was higher than Sputnik V and Covaxin vaccines. Injection site pain (62.1%), fatigue (43.9%), muscle pain (42.5%), and fever (40.6%) were the most common side effects in all three vaccines. Side effect frequency was higher in the female group (90.6%) than the male group (79.5%). The prevalence of side effects with Sputnik V and Covaxin vaccines was reduced in the elderly. Moreover, the prevalence of side effects was higher in the case of convalescent patients (92.4 %) than in the group with no history of infection. The prevalence of side effects was higher in person with a BMI above 25 in the AZD-1222 and Covaxin vaccines. CONCLUSIONS: The most common side effects of the Sputnik-V, AZD-1222, and Covaxin vaccine among Birjand (Iran) healthcare workers were injection site pain, muscle pain, fatigue, fever, and headache. Age and gender were the most important variables in the prevalence of vaccine side effects.