Pre-vaccination evolution of antibodies among infants 0, 3 and 6 months of age: A longitudinal analysis of measles, enterovirus 71 and coxsackievirus 16

Abstract Background 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. Methods In 2013–2014, we collected sera at ages 0, 3 and 6 months 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. Results Pre-vaccination monotonic antibody decreases were observed for measles (1410, 195 and 22 mIU/ml, p  Conclusions 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.