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Technical update on Pre-exposure Prophylaxis (PrEP)

Publication year: 
Corporate author: 
World Health Organisation
Publication details: 
Geneva:WHO, 2015

The development of oral pre-exposure prophylaxis began in the early part of the last decade. Proof of concept was suggested through comparisons with prevention of mother-to-child transmission and post-exposure prophylaxis and was supported by animal models, both in mice (1) and in macaques (2–5). Safety was demonstrated with a Phase II study conducted in west Africa (6). Soon after, enrollment in Phase III efficacy trials of both topical and oral PrEP among different groups began:

• Oral PrEP among persons who inject drugs in Bangkok, Thailand in 2005 (7) ;
• Oral PrEP among men and transgender women who have sex with men (MSM) in multiple countries (8) and among highly sexually active men and women in Botswana (9) and topical PrEP among young women at risk in South Africa (10) in 2007;
• Oral PrEP among serodiscordant heterosexual couples in Kenya and Uganda in 2008 (11) ; and among young women at high risk of HIV in 2009 (12) ;
• Oral and topical PrEP among women in Uganda, South Africa and Zimbabwe in 2009 (13).