Sustained Seropositivity of Varicella in Healthy Populations in Guangzhou, China

A seroepidemiological study conducted from 2020 to 2022 in Guangzhou, China, aimed to evaluate varicella antibody levels. We measured varicella antibody concentrations using an enzyme-linked immunosorbent assay (ELISA) in a cohort of 3,300 subjects. The mean varicella IgG-specific antibody level was 171.2 mIU/mL (95% CI: 158.9, 184.4), with an overall positivity rate of 67.00% (95% CI: 65.37, 68.60). Varicella antibody levels were found to be influenced by age, vaccination dosage, and history of varicella infection. Notably, antibody concentrations increased with age and the number of vaccinations. Subjects with a vaccination history maintained positive antibody levels six years post-vaccination. We recommend two doses of the varicella vaccine for both children and adults. Before incorporating the varicella vaccine into Guangzhou's routine immunization programs, a comprehensive assessment of disease burden and the economic viability of vaccination strategies is essential.