Dengue surveillance in preparation for field vaccine trials.

Preparations for dengue vaccine trials as well as vaccine introduction strategies require laboratory-based surveillance on an international and coordinated level. The Pediatric Dengue Vaccine Initiative (PDVI) has developed an international consortium of field sites in Latin America and Asia. These sites conduct community- based and enhanced passive laboratory-based surveillance of dengue fever. Through this consortium, PDVI is facilitating harmonized laboratory-based surveillance processes, so that disease incidence can be compared between different regions and countries. This process prepares sites for the rigorous case detection, diagnosis, recording and analysis to meet good clinical practice standards necessary for clinical dengue vaccine trials. In addition to several years of laboratory-based dengue surveillance data, dengue vaccine trial site criteria include low population migration of an endemic disease area, documentation of other local flavivirus epidemiology, good medical infrastructure, political stability, and country and target population commitment to vaccine trials and need for vaccine. Prevention of dengue fever is the most suitable primary end point for a proof-of-concept dengue vaccine trial. However, such trials may provide insufficient information for stratified analysis of outcomes according to varied risk factors and virus serotype. Consequently large community-based demonstration trials may be necessary.