Mumps antibody levels after MMR vaccination in a population in Changning District of Shanghai

ObjectiveTo evaluate the dosage effect of measles， mumps and rubella combined attenuated live vaccine （MMR） vaccination on seroprevalence of mumps.

MethodsA cross-sectional study was conducted among people in Changning District of Shanghai aged 1 month to 19 years old （n=1 816） in Mar.－Sep. 2017. Blood samples were analyzed for mumps antibodies using enzyme-linked immunosorbent immunoglobulin G （IgG） assays.

ResultsMumps antibody seropositivity was 94.59% in 2 years old children and maintained at 98.18%-100.00% from 4 to 9 years old. The seropositivity began to decrease since 10 years， and it was 88.33% （95%CI： 81.20%-93.47%） at age of 12 years. In 12-19 years age group， individuals with 3 doses of mumps-containing vaccines had the highest seropositivity （93.88%） and individuals with 1 or 0 doses had the lowest seropositivity （68.75%）.

ConclusionTwo-dose MMR immunization in Shanghai induces a sharp increase in mumps antibody levels in the corresponding age groups. The antibody levels decline gradually with time since the second dose. Vaccine dosage is positively associated with mumps IgG seropositivity and geometric mean concentrations （GMC） in 12-19 years old.