The 13th WHOPES working group (13th WG) (WHO, 2009a) held from 28-30 July 2009, reviewed the following product claim for PermaNet® 3.0 “improved efficacy against pyrethroid-resistant malaria vectors” and concluded that the claims were too broad as the resistance mechanisms were not stated and there was no reference product. The narrowed claim “Increased* efficacy against pyrethroid resistant** malaria vectors” was communicated to WHOPES and included on all marketing material, with effect from 20th July 2009. This narrowed claim takes into consideration the issues raised by the 13th WG to include a more specific claim and targeted product profile. The 13th WG meeting also suggested that experimental hut comparisons with the company’s existing WHOPES recommended LN, unwashed and washed may be a suitably controlled method to test increased efficacy in terms of mortality and blood feeding inhibition against target species with known resistance mechanisms in different settings. Experimental hut comparisons of unwashed and washed PermaNet® 3.0 and PermaNet® 2.0 have been conducted in areas with known resistance mechanisms in Burkina Faso, Cameroon and Vietnam. Significantly higher mortality and blood feeding inhibition with PermaNet® 3.0 was observed in Burkina Faso and significantly higher mortality with PermaNet® 3.0 was observed in Cameroon and Vietnam. Data from these studies can be found in the 12th WG report (WHO, 2009b) and PermaNet® 3.0 brochure¹.

Vestergaard Frandsen is currently undertaking further studies to generate additional data in Ivory Coast², Cameroon, Nigeria and DRC to provide evidence to the national programmes on the product performance. Vestergaard Frandsen is committed to conduct similar studies or other studies with a suitable protocol in additional countries where this product could be of relevance.

*relative to PermaNet® 2.0
**as tested with oxidase, esterase and kdr resistant mosquitoes