ABSTRACT
Background: In China, one dose measles-mumps-rubella vaccine (MMR) was administered to children aged 18–24 months. The mumps incidence was still high. Data on the waning immunity to mumps after MMR vaccination are limited. This study aimed to describe the waning immunity to mumps in kindergarten and primary school children to provide a scientific basis for confirming an optimal age for a second dose.
Methods: An observational, prospective study on one-dose MMR in children in kindergarten and primary school was conducted from 2015 to 2016. Waning immunity to mumps in terms of seropositivity and geometric antibody concentration (GMC) with time was analyzed.
Results: In total, 7436 eligible subjects in kindergarten (3435) and primary school (4001) were included in 2015. The overall GMC (201.7 U/ml) and seropositivity (75.4%) to mumps antibodies in 2016 were significantly lower compared to those in 2015 (218.7 U/ml, 78.4%). Asymptomatic infection occurred within one year in 8.8% of children who received one-dose MMR.
Conclusions: Children who received one-dose MMR in kindergarten and primary school were at high risk of mumps infection, and waning immunity occurred with time. Determining the optimal age for the second dose of MMR in children should be prioritized to prevent mumps epidemics.
Acknowledgments
We would like to thank all the following CDCs in the Jiangsu province for their field works: Changzhou Center for Disease Control and Prevention (CDC), Huaian CDC, Lianyungang CDC, Taizhou CDC, Zhenjiang CDC, Xuzhou CDC, Wujin district CDC, Lianshui county CDC, Ganyu district CDC, Gaogang district CDC, Tongshan district CDC, and the Danyang county CDC.
Author contributions
Yuanbao Liu, Fengc-Cai Zhu, Fenyang Tang, and Zhihao Liu were involved in the study design, data analysis, article drafting, critical revision of the article and final approval. Zhiguo Wang, Xiang Sun, Yan Xu were involved in the fields works including recruitment and following-up of participants and data collection. Xiuying Deng, Ying Hu, Peishan Lu, Hongxiong Guo were involved in the laboratory works, critical revision of the article.
Declaration of interest
The authors declare no conflicts of interest. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.
Clinical trial registration: NCT02901990