ABSTRACT
Objective@#To investigate the serum anti-mumps IgG antibody levels among children aged 0 to 4 years in Haishu District, Ningbo City, Zhejiang Province, so as to provide insights into improvements for mumps vaccination program.@*Methods@#Children aged 0 to 4 years were sampled from Haishu District using a stratified random sampling method in 2016 (before adjustment of the mumps vaccination program) and 2022 (after adjustment of the mumps vaccination program). Participants' demographics were collected using questionnaires, and the coverage of mumps-containing vaccines was collected from the Ningbo Municipal Immunization Information System. Serum anti-mumps IgG antibody was measured using enzyme-linked immunosorbent assay (ELISA), and the seroprevalence of anti-mumps IgG antibody and geometric mean concentration (GMC) were estimated among children aged 0 to 4 years in 2016 and 2022.@*Results@#A total of 464 children were enrolled in 2016, including 250 boys (53.88%) and 214 girls (46.12%), and there were 301 children receiving mumps-containing vaccines (64.87%). The seroprevalence of anti-mumps IgG antibody were 48.08%, 34.44%, 81.11%, 84.44% and 84.44%, and GMC were 233.86, 351.77, 333.66, 362.29 and 410.72 U/mL. A total of 456 children were recruited in 2022, including 236 boys (51.75%) and 220 girls (48.25%), and there were 427 children receiving mumps-containing vaccines (93.64%). The seroprevalence of anti-mumps IgG antibody were 72.73%, 95.00%, 100.00%, 98.68% and 99.04%, and GMC were 524.05, 1 229.69, 1 623.64, 788.01 and 738.41 U/mL. Higher seroprevalence and GMC of anti-mumps IgG antibody was seen in 2022 than in 2016 among children at all age groups (P<0.05).@*Conclusion@#Following adjustment for vaccination programs, the seroprevalence and GMC of anti-mumps IgG antibody significantly increased among children at ages of 0 to 4 years in Haishu District.