Analysis of sero-epidemiological characteristics of varicella in healthy children in Wuxi, China.

The aim of this study was to evaluate seroepidemiology of varicella in Wuxi, China, after two doses of immunization of varicella vaccine (VarV) for better control of varicella transmission. Participants were selected randomly by multistage stratified sampling. The positive rate of antibody and geometric antibody titer (GMC) was determined with enzyme-linked immunosorbent assays. Logistic and linear regressions were used to analyze the correlations between antibody seropositivity, GMCs, and corresponding factors. Serum samples (n = 697) were obtained from healthy children <7 years-of-age. Seropositivity and GMC were 67.84% and 190.97 mIU/mL, respectively, in subjects receiving two doses of VarV. Multivariate analysis revealed that both the rate of varicella-zoster virus immunoglobulin G seropositivity and GMC in vaccinated subjects were higher compared to those who had not been vaccinated. The strongest overall response was observed in subjects with two doses of VarV (4.055, 95% CI: 2.774 ~ 5.928). In 470 subjects with a history of VarV application, the antibody GMC value was reduced 4 years after vaccination. Two-dose vaccination with VarV was an effective prevention strategy varicella and should be included in a national immunization program.