COVID-19 Vaccination Adverse Events in Children: An Investigation with a Control Group in Tabriz Metropolitan City

The occurrence of adverse events following vaccination with the novel coronavirus disease 2019 (COVID-19) vaccine in children remains somewhat unclear, with only a limited number of population-based studies having been conducted in this age group. The objective of this study is to ascertain the short-term adverse events associated with the Sinopharm and Soberana (Pasto CoVac) vaccination in children between the ages of 5 and 12. This study employs an observational design with a control group. The cluster sampling method was employed to recruit the study samples, with healthcare centers and mass vaccination centers of Tabriz designated as clusters. The ratio of the vaccinated and unvaccinated groups was 2:1, respectively. Information was gathered via telephone interviews with the parents or guardians of the subjects. The data were analyzed using a mixed-effect logistic regression model. In this study, a total of 913 children were investigated, comprising 577 vaccinated and 336 unvaccinated children. The results demonstrated that the most frequent complication among the vaccinated children was injection site pain, occurring in 178 cases (30.8%, 95% CI:( 27%, 35%)) The most frequently reported systemic adverse events among vaccinated and unvaccinated children were fever (9.0% vs. 3.6%, p = 0.003), fatigue (5.5% vs. 0.9%, p = 0.002), and headache (2.9% vs. 0.6%, p = 0.032). No serious adverse events, including myocarditis, multisystem inflammatory syndrome (MIS), or hospitalization, were reported. The odds of experiencing any symptoms in the vaccinated group, adjusted for potential confounding variables, were significantly higher than in the control group (adjusted OR = 4.71, CI 95%: (3.04, 7.26), with a p-value of less than 0.001. The results indicate that the Sinopharm and Soberana (PastoCoVac) vaccines did not have any serious adverse effects. Moreover, it appears that some of the reported adverse events in other studies may be overestimated due to the absence of a control group.