Original Article: bit.ly/1oSaLUI
In a recent BMJ Blog Dr Rupert Whitaker cast a critical eye on Pre-Exposure Prophylaxis (PrEP) for the prevention of HIV infection, questioning its role as a public health intervention. The piece is challenging and although it rightly emphasises the need for a carefully planned implementation, it contains a number of factual inaccuracies and conceptual misunderstandings that need to be addressed.
PrEP and/or condoms
The blog starts with the statement that “[PrEP] works in just the same way as condoms do in real life”. This is not the case and it is something important to understand. Condoms provide a physical barrier which prevents the transmission of HIV; PrEP offers a chemical barrier which prevents the acquisition of HIV. The distinction between transmission and acquisition is not trivial.
With condoms, an uninfected person is physically protected against exposure to the virus; with PrEP a person can be exposed to the virus but the presence of enough antiviral drugs at the point of entry will protect them against viral infection. A more judicious comparison would have been between PrEP and treatment.
As a consequence, it is all or nothing with condoms whilst PrEP is more forgiving.
Truvada is currently the only drug approved for PrEP and only in the USA where it is prescribed as a daily regimen for the prevention of HIV infection in HIV negative people. Adherence to the regimen is crucial to PrEP effectiveness but missing a pill occasionally will not affect the protection PrEP offers as dramatically as would not using condoms on a random sexual encounter.
Full text of article available at link below: bit.ly/1oSaLUI