• Jiaxin Zhou, Yonghong Zhou, Kaiwei Luo, Qiaohong Liao, Wen Zheng, Hui Gong, Huilin Shi, Shanlu Zhao, Kai Wang, Qi Qiu, Bingbing Dai, Lingshuang Ren, Lili Wang, Lidong Gao, Meng Xu, Nuolan Liu, Wanying Lu, Nan Zheng, Xinhua Chen, Zhiyuan Chen, Juan Yang, Simon Cauchemez, and Hongjie Yu.
• School of Public Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China.
• Bmc Med. 2022 Nov 9; 20 (1): 436.

BackgroundA major hand-foot-and-mouth disease (HFMD) pathogen, coxsackievirus A16 (CVA16), has predominated in several of the last 10 years and caused the largest number of HFMD outbreaks between 2011 and 2018 in China. We evaluated the efficacy of maternal anti-CVA16 antibody transfer via the placenta and explored the dynamics of maternal and natural infection-induced neutralizing antibodies in children.MethodsTwo population-based longitudinal cohorts in southern China were studied during 2013-2018. Participants were enrolled in autumn 2013, including 2475 children aged 1-9 years old and 1066 mother-neonate pairs, and followed for 3 years. Blood/cord samples were collected for CVA16-neutralizing antibody detection. The maternal antibody transfer efficacy, age-specific seroprevalence, geometric mean titre (GMT) and immune response kinetics were estimated.ResultsThe average maternal antibody transfer ratio was 0.88 (95% CI 0.80-0.96). Transferred maternal antibody levels declined rapidly (half-life: 2.0 months, 95% CI 1.9-2.2 months). The GMT decayed below the positive threshold (8) by 1.5 months of age. Due to natural infections, it increased above 8 after 1.4 years and reached 32 by 5 years of age, thereafter dropping slightly. Although the average duration of maternal antibody-mediated protection was < 3 months, the duration extended to 6 months on average for mothers with titres ≥ 64.ConclusionsAnti-CVA16 maternal antibodies are efficiently transferred to neonates, but their levels decline quickly. Children aged 0-5 years are the main susceptible population and should be protected by CVA16 vaccination, with the optimal vaccination time between 1.5 months and 1 year of age.© 2022. The Author(s).

23 keywords...

hide…