Waning of maternal antibody against measles virus in Shufu, China

Abstract

ABSTRACT Background: As measles vaccination coverage has increased, measles infection has shifted to the population of infants. We conducted a follow-up seroepidemiological study among mothers and their infants to evaluate measles seroprevalence and the persistence of maternal measles antibody in Shufu, Kashgar from 2018 to 2020. Methods: Maternal venous blood and cord blood was obtained among mothers and their infants at 0, 3, 5, 8, 9, and 12 months of age. An enzyme-linked immunosorbent assay was used for quantitative measurement of measles antibodies. We analyzed the correlation between maternal and neonatal measles antibodies, and antibodies persistence after infants were born. Results: The overall neonatal maternal ratio was 2.38 (95%CI: 2.05–2.71). The measles antibodies for mothers and newborns were 438.93 IU/mL (95%CI: 409.47–470.51 IU/mL) and 440.10 IU/mL (95%CI: 410.82–471.48 IU/mL), respectively. Neonatal measles antibodies were dropping after birth and then beginning to increase starting at 8 months of age. Conclusions: Infant measles antibody levels progressively declined after birth regardless of maternal measles antibody levels. Efforts should be carried out to eliminate measles.