Reported adverse events following monovalent varicella vaccination in children aged 1–12 years: a VAERS disproportionality analysis, 1995-2026

Background Varicella vaccines have been widely used in children, but comprehensive post-marketing safety evaluations in the pediatric population remain limited. Methods We analyzed 55,475 adverse event (AE) reports following varicella vaccination in children aged 1–12 years from the U.S. Vaccine Adverse Event Reporting System (VAERS) between 1995 and 2026. Descriptive analyses were performed for demographic and clinical characteristics. Disproportionality signals were detected using Proportional Reporting Ratio (PRR) and Reporting Odds Ratio (ROR), with false discovery rate controlled by Benjamini-Hochberg (BH) correction. Stratified analyses were conducted by age and sex. Results The most frequently reported adverse events were rash (a = 7,218, ROR = 2.09, PRR = 2.05), infection (a = 5,694, ROR = 10.76, PRR = 10.43), dermatitis bullous (a = 3,563, ROR = 37.28, PRR = 36.51), viral infection (a = 2,173, ROR = 9.67, PRR = 9.56) and rash vesicular (a = 2,137, ROR = 20.94, PRR = 20.68). Most cases (53.72%) resolved completely. Children aged 1–2 years accounted for 52.00% of reports. Initial analysis identified 135 positive signals at the Preferred Term level, which were reduced to 111 after multiplicity correction. Injection site reactions predominated in older children (3–6 and 7–12 years), while systemic events were more common in the youngest group. Sex differences were minimal. Serious adverse events occurred in 5.94% and deaths in 0.30% of reports. Conclusion This analysis of VAERS reports describes a generally non-serious and self-limiting reporting profile for varicella vaccines in children aged 1–12 years. These findings support continued pharmacovigilance to inform evidence-based vaccination policies and targeted risk communication, but they do not confirm a favorable safety profile or establish causality, incidence, or absolute risk. Further denominator-based studies are needed to validate these observations.