Once optimal coverage with either insecticide-treated nets (ITNs) or indoor residual spraying (IRS) has been achieved, programmes may consider deploying the other intervention as an approach to prevent, manage and mitigate insecticide resistance. The ITN and IRS products selected for co-deployment must not contain the same insecticide class(es). For instance, IRS with a pyrethroid should not be deployed in the same households or areas as ITNs. The decision to deploy a second vector control intervention should only be taken after conducting a prioritization analysis across malaria interventions, not just vector control, to ensure maximum impact of any additional resources.