COVID-19 vaccines breakthrough infection and adverse reactions in medical students: a nationwide survey in Iran.

Introduction: There are different types of COVID-19 vaccines approved worldwide. Since no national studies focus on vaccine-related adverse reactions and breakthrough cases, this study aimed to investigate the rate of adverse events and COVID-19 infection in medical students in Iran.
Methods: This retrospective cohort study included Iranian medical students who received two doses of COVID-19 vaccines. The medical team gathered the demographic characteristics, comorbidities, type of vaccine, adverse events following vaccination, and history of COVID-19 infection data through a phone interview. The frequency of adverse events and breakthrough infection was stratified by vaccine type (ChAdOx1-S, Gam-COVID-Vac, and BIBP-CorV).
Results: A total of 3,591 medical students enrolled in this study, of which 57.02% were females, with a mean age of 23.31 + 4.87. A PCR-confirmed and suspicious-for-COVID-19 breakthrough infection rate of 4.51 and 7.02% was detected, respectively. There was no significant relation between breakthrough infection and gender, BMI, blood groups, and comorbidities. However, there was a significant difference in breakthrough infection rate among different types of vaccines ( p = 0.001) and history of COVID-19 infection ( p = 0.001). A total of 16 participants were hospitalized due to COVID-19 infection after vaccination for reasons such as dyspnea, abnormal imaging, or decreased oxygen saturation. No severe infection or death was observed in the studied population.
Conclusion: Vaccination prevented severe COVID-19 infection, although a high breakthrough infection rate was evident among Iranian medical students during the Delta variant's peak. Vaccine effectiveness may be fragile during emerging new variants and in high-exposure settings. Moreover, adverse events are rare, and the benefits of vaccination outweigh the side effects. However, many limitations challenged this study, and the results should be cautious.
Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
(Copyright © 2024 Allahgholipour, Safavi-Naini, Shekarriz Foomany, Eskandari, Nazari Rostami, Honarvar, Mohammadi, Khalili, Ilaghi, Afshar, Amini Baghbadorani, Moghimi, Chamani Goorabi, Mehrparvar, Safari, Nakhli, Mahmoudabadi, Seifadini, Sheikhansari, Khojastehfar, Mahdavi, Mohammadi, Ashrafi Barzideh, Akbarzadeh, Delavarpour Moghadam, Tavakoli Pirzaman, Barary and Emamhadi.)