The need for PrEP

Other sections in Preventing HIV bear witness to the possible need for PrEP. Increases in condom use have proved difficult to achieve in many populations. An effective vaccine against HIV may still be a decade or two away, if it is feasible at all. Though we have proof of the efficacy of topical microbicides,¹ we await a confirmatory study, and developing usable formulations will take years yet. Male circumcision, though effective, will only protect certain groups. Post-exposure prophylaxis is also effective, but not accessed often enough to make a difference to HIV incidence on a population level.

PrEP, on the other hand, could be adopted quite quickly if its efficacy and applicability is sufficiently well demonstrated to convince funders and providers to make it available. What could be simpler than taking a pill which could protect you against HIV? If further studies prove high efficacy, if it is economically feasible, if it is safe in the long term and if the right people take it at the right time…we may have something as effective as a vaccine in the shape of a pill you can hold in your hand now.

There are historical precedents for the idea of PrEP. The classic one is the use of quinine against malaria. Henry Hobhouse’s book, Seeds of Change,² describes how the anti-malaria drug quinine (in ‘tonic water’) enabled Europeans to colonise parts of the world where previously life had been impossible due to malaria. Prophylaxis is effective against other infectious diseases (e.g. isoniazid for tuberculosis) and other health conditions (e.g. statins, used by people who have already had a heart attack, to prevent a second heart attack).

However, the closest parallel, in terms of the population that may need to take PrEP, the reason for taking it and challenges to its development and widespread use, is probably the contraceptive pill.