Fu Chuanxi, Shen Jichuan, Lu Long, Li Yajing, Cao Yimin, Wang Ming, Pei Sen, Yang Zhicong, Guo Qing, Shaman Jeffrey
Zhejiang Chinese Medical University, Hangzhou, China; Guangzhou Center for Disease Control and Prevention, Guangzhou, China.
Guangzhou Center for Disease Control and Prevention, Guangzhou, China.
Vaccine. 2017 Jul 5;35(31):3817-3822. doi: 10.1016/j.vaccine.2017.06.002. Epub 2017 Jun 10.
Due to waning levels of maternal antibodies (measles; enterovirus 71, EV71; and coxsackievirus A16, CoxA16), some infants may lose protection against infection prior to vaccination. Using a longitudinal design, we examine how maternal antibody levels evolve over time in infants prior to vaccination.
In 2013-2014, we collected sera at ages 0, 3 and 6months from infants. We assayed for levels of measles IgG antibody (717, 233 and 75 sample sera tested at months 0, 3 and 6, respectively), and neutralizing antibodies for EV71 and CoxA16 (225, 217, and 72). Demographic and health information were collected, and a linear mixed model (LMM) was used to describe antibody levels over time.
Pre-vaccination monotonic antibody decreases were observed for measles (1410, 195 and 22mIU/ml, p<0.001), EV71 (1:19.9, 6.3 and 4.5, p<0.001) and CoxA16 (1:16.3, 5.9, and 4.5, p<0.001). At 6months of age, only 2.7% (95%CI, 0.6-8.3), 6.8% (95%CI, 2.7-14.4) and 5.6% (95%CI, 1.9-12.7) of infants were antibody positive for measles, EV71 and CoxA16, respectively. LMM findings indicated that infants with higher antibody titers at birth experienced a greater loss of antibody level. An infection rate of 1.3% (95%CI, 0.1-6.1) was reported for both EV71 and CoxA16.
Further modifications of vaccination strategies for measles, earlier vaccination for EV71 infection, and deployment of a CoxA16 vaccine need to be considered to limit infection among the very young.
由于母体抗体（麻疹；肠道病毒71型，EV71；以及柯萨奇病毒A16型，CoxA16）水平下降，一些婴儿在接种疫苗前可能会失去对感染的抵抗力。我们采用纵向研究设计，研究婴儿在接种疫苗前母体抗体水平随时间的变化情况。
在2013年至2014年期间，我们收集了婴儿在0、3和6个月龄时的血清。我们检测了麻疹IgG抗体水平（分别在0、3和6个月时检测了717、233和75份样本血清），以及EV71和CoxA16的中和抗体（分别检测了225、217和72份样本）。收集了人口统计学和健康信息，并使用线性混合模型（LMM）来描述抗体水平随时间的变化。
在接种疫苗前，观察到麻疹（1410、195和22mIU/ml，p<0.001）、EV71（1:19.9、6.3和4.5，p<0.001）和CoxA16（1:16.3、5.9和4.5，p<0.001）的抗体水平呈单调下降。在6个月龄时，分别只有2.7%（95%置信区间，0.6 - 8.3）、6.8%（95%置信区间，2.7 - 14.4）和5.6%（95%置信区间，1.9 - 12.7）的婴儿麻疹、EV71和CoxA16抗体呈阳性。线性混合模型的研究结果表明，出生时抗体滴度较高的婴儿抗体水平下降幅度更大。据报告，EV71和CoxA16的感染率均为1.3%（95%置信区间，0.1 - 6.1）。
需要考虑进一步调整麻疹疫苗接种策略，提前接种EV71感染疫苗，并部署CoxA16疫苗，以限制幼儿中的感染。
