WHO recommends pre-exposure prophylaxis (PrEP) as an additional prevention option for HIV-negative individuals at substantial risk of HIV infection, as part of combination prevention approaches. HIV drug resistance was rarely reported among PrEP users diagnosed with HIV in randomized controlled trials or open label studies.

However, PrEP-selected HIV drug resistance could potentially negatively impact the effectiveness of antiretroviral therapy (ART) options among PrEP users who acquire HIV. This is because there is a potential for overlapping resistance profiles between antiretroviral drugs used for both PrEP and first-line ART.

Therefore, WHO recommends that PrEP scale-up be accompanied by surveillance of HIV drug resistance, as resistance may compromise the effectiveness of first-line ART among PrEP users who acquire HIV.