Comparison of four types of vaccines Sinopharm, AstraZeneca, Sputnik V, and Covaxin in terms of morbidity and severity of COVID-19 in vaccinated personnel of several selected medical centers, Tehran, Iran

Abstract   BACKGROUND: The main purpose of the present study was to compare four vaccines: Sinopharm, AstraZeneca, Sputnik V, and Covaxin, in terms of morbidity and severity of COVID-19 after vaccination in healthcare workers working in selected medical centers in Tehran, Iran.    MATERIALS AND METHODS: This descriptive-analytical cross-sectional study was conducted among 1474 students, staff of a medical university, and seven selected hospitals in Tehran for two months between June to August 2021; Data were collected by a questionnaire, Participants had received one or two doses of mentioned vaccines and at least twenty days had passed since they received their first dose of the vaccine. Incomplete questionnaires were excluded from statistical analysis.   RESULTS: 35.9% (n=531) of participants had a history of COVID-19 before vaccination. There was no significant relationship between the history of the previous infection with COVID-19 before vaccination and the occurrence of COVID-19 after vaccination in any of the vaccines. For all four vaccines, the occurrence of the disease after receiving the second dose was less than 10% (Sinopharm 3.1%, AstraZeneca 6.4%, Sputnik V 6.4%, Covaxin 6.8%),. There was a statistically significant difference among all vaccines mentioned above in terms of COVID-19 infection after receiving the second dose (p = 0.042) for all four vaccines. The severe form of the disease, which requires referral to medical centers, was less than 10% among patients with the disease after vaccination. There was no significant difference between the vaccines regarding disease severity in patients.  CONCLUSION: The severity of COVID-19 was not significantly different in the infected patients after the first or second dose. Also, the previous infection with COVID-19 before vaccination was not associated with the occurrence of COVID-19 after vaccination in any of the four vaccines. To sum up, this finding can be applied by policymakers to have a better vision.    

Comparison of four types of vaccines Sinopharm, AstraZeneca, Sputnik V, and Covaxin in terms of morbidity and severity of COVID-19 in vaccinated personnel of several selected medical centers, Tehran, Iran Keywords:

Vaccination , Covid-19 , Severity , Morbidity , Immunity