Abstract
BACKGROUND: Measles and rubella are vaccine-preventable diseases targeted for elimination in most World Health Organization regions, and China is considered to have momentum towards measles elimination. Therefore, this study aimed to assess the population immunity levels against measles and rubella in Zhejiang Province in China in order to provide valuable insights for informing future public health measures and contributing to the ongoing global campaign against these diseases. MATERIALS AND METHODS: A cross-sectional serological survey was conducted in 2022. A total of 2740 blood samples were collected from healthy individuals spanning the age range of 0-59 years, representing diverse demographic strata across 11 prefectures in Zhejiang Province in China. The sera were tested for measles and rubella IgG antibodies to determine positivity rates and geometric mean concentrations (GMCs). RESULTS: The overall positivity rate for the measles IgG antibody was 85.3%, with a GMC of 588.30 mIU/mL. The positivity rate for the rubella IgG antibody was 70.9%, and the GMC was 35.30 IU/mL. Measles IgG antibody positivity rates across the 0-11 months, 12-23 months, 24-35 months, 3-5 years, 6-9 years, 10-14 years, 15-19 years, 20-29 years, and 30-59 years age groups were 63.1%, 92.5%, 97.0%, 94.0%, 85.8%, 77.3%, 86.9%, 84.9%, and 88.7%, respectively (trend χ(2) = 118.34, p < 0.001). Correspondingly, rubella antibody positivity rates for these same age brackets were 55.9%, 87.9%, 94.7%, 88.2%, 69.9%, 54.2%, 72.6%, 67.5%, and 74.3% (trend χ(2) = 199.18, p < 0.001). Both univariate and multivariate analyses consistently demonstrated that age, immunization history, and differing economic levels were significant factors contributing to variations in antibody levels. CONCLUSIONS: The seroprevalence of measles and rubella was lower than that required for herd immunity. Periodic vaccination campaigns should be launched to increase immunity.