Two models for changes of EV71 immunity in infants and young children

Abstract

Human enterovirus 71 (EV71) has been associated with outbreaks of hand-foot-and-mouth disease (HFMD) in China. Susceptibility to EV71 is associated with age, but few studies have been accomplished to measure such a relationship. A better understanding of the connection between susceptibility and age is necessary to develop strategies for control of HFMD. In 2010, a survey of an epidemic of EV71 was conducted in a northern city of Jiangsu Province in China. Samples were tested serologically to identify the EV71 neutralizing antibody. Two different mathematical models have now been employed to describe how this antibody varied with age, and parameters in the model were estimated from survey data. Both models depicted the variations in EV71-neutralizing antibody. Seroprevalence was high for neonates but decreased to near zero at 5 months of age. Subsequently, the EV71 antibody levels increased and then remained stable after about 36 months. For models 1 and 2, values for the coefficient of determination (R(2)) were 0.9458 and 0.9576, and values for root mean square error (RMSE) were 0.0755 and 0.0752, respectively. Model 2, formulated from the characteristics of development of the immune system, was more reliable than model 1, formulated from survey data, because the impact of the survey on the structure of the model was removed. Moreover, model 2 provided the possibility to define the parameters in a biological sense.

Serological detection and analysis of anti-VP1 responses against various enteroviruses (EV) (EV-A, EV-B and EV-C) in Chinese individuals

“…The viral structural proteins VP1, VP2, VP3 are highly structured, comprising a beta sheet, and are likely the principal targets for the host’s humoral immunity responses 16 18 19 22 23 24 . The neutralizing antibody assay has been the only effective serological assay to successfully assess human EV epidemics 25 26 27 28 . However, this technique has provided little cumulative evidence to evaluate the overall serological prevalence levels of various EV types and species.…”