Calibration of an intrahost malaria model and parameter ensemble evaluation of a pre-erythrocytic vaccine

Malaria Journal

Research

Kevin A McCarthy¹  Grace H Huynh¹  Edward A Wenger¹  Philip A Eckhoff¹ 

[1] Institute for Disease Modeling, 1555 132nd Ave NE, 98005, Bellevue, WA, USA;

关键词: Pre-erythrocytic;    Calibration;    Ensemble;    Vaccine;    Model;   

DOI  :  10.1186/1475-2875-14-6

 received in 2014-09-26, accepted in 2014-12-16,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundA pre-erythrocytic vaccine could provide a useful tool for burden reduction and eventual eradication of malaria. Mathematical malaria models provide a mechanism for evaluating the effective burden reduction across a range of transmission conditions where such a vaccine might be deployed.MethodsThe EMOD model is an individual-based model of malaria transmission dynamics, including vector lifecycles and species-specific behaviour, coupled to a mechanistic intrahost model of malaria parasite and host immune system dynamics. The present work describes the extension of the EMOD model to include diagnoses of severe malaria and iterative calibration of the immune system parameters and parasite antigenic variation to age-stratified prevalence, incidence and severe disease incidence data obtained from multiple regions with broadly varying transmission conditions in Africa. An ensemble of calibrated model parameter sets is then employed to evaluate the potential impact of routine immunization with a pre-erythrocytic vaccine.ResultsThe reduction in severe malaria burden exhibits a broad peak at moderate transmission conditions. Under sufficiently intense transmission, a vaccine that reduces but does not eliminate the probability of acquisition from a single challenge bite may delay infections but produces minimal or no net reduction. Conversely, under sufficiently weak transmission conditions, a vaccine can provide a high fractional reduction but avert a relatively low absolute number of cases due to low baseline burden.ConclusionsRoll-out of routine immunization with pre-erythrocytic malaria vaccines can provide substantial burden reduction across a range of transmission conditions typical to many regions in Africa.

【 授权许可】

CC BY   
© McCarthy et al.; licensee BioMed Central. 2015