Theoretical scenarios for the use of ivermectin in humans and/or peri-domestic animals according to behaviour of dominant vectors. In a the coloured squares are used for illustration purposes as there are no clear limits for these scenarios. There are no “pure” scenarios in which mosquitoes bite only humans outdoors, so ivermectin should always be envisaged as a complementary measure. b shows how ivermectin use in a specific setting could be tailored according to the behaviour of the main vectors. It has been adapted with permission from Killeen et al.