ASTMH 2014, Teun Bousema: “Evaluating the impact of transmission blocking vaccines in the field”

In collaboration with ASTMH, ImageAV & presenters, MESA brings you this webcast.

Title: Evaluating the impact of transmission-blocking vaccines in the field

Abstract:

This talk is part of the ASTM symposium ‘Accelerating the Development of Transmission Blocking Vaccines for Malaria Elimination’. Transmission-blocking vaccines (TBVs) represent a promising tool in the fight to eliminate malaria. However, the concept of vaccination to elicit antibodies that act by blocking transmission from an infected person to others in the community (by inhibiting the development of infectious sporozoites in mosquitoes) is challenging. The questions facing developers of TBVs include how to demonstrate effectiveness in clinical trials so such vaccines might be approved by regulatory authorities, and what is needed to accelerate this approval? Early clinical trials of a TBV can determine the vaccine’s ability to elicit functional antibodies in immunized subjects. When moving to large-scale field trials, the question is how to demonstrate the effectiveness of a TBV where the reduction of malaria transmission in a community needs to be demonstrated. To address this question, it is important to map the regulatory pathway and understand the role of laboratory tools as potential surrogate markers of efficacy in clinical trials. This symposium will cover topics that address the issues faced when developing a TBV, and help explore potential pathways to regulatory approval. The talks will include the experience of a vaccine developer testing a TBV candidate in a Phase 1 clinical trial, as well as some of the challenges faced when a vaccine is tested in the field. The information required to assess the level of malaria transmission-blocking activity needed to lead to elimination under a given transmission setting (biting rate) will be presented in a talk that uses murine models of transmission. Another speaker will discuss the development of human challenge models that measure malaria transmission from man to mosquito, which may be useful for developing TBVs and accelerating approval. The final presentation will cover the regulatory pathways for approval of TBVs.