Shobha Shukla, CNS (Citizen News Service) Dr Suwat Chariyalertsak, Director, RIHES, CMU Pre-exposure prophylaxis or PrEP, is a relatively new concept of "treatment as prevention" against HIV for those HIV uninfected persons who might be at risk of contracting the virus. Currently, only Truvada, a two-drug (Tenofovir Disoproxil Fumarate/ Emtricitabine - TDF/FTC) combination pill, is available to be taken for PrEP. Approved by US FDA in July 2012, Truvada is 100% effective in preventing HIV in those who take this once a day pill at least 4 or more days a week. But studies have revealed that many find it difficult to comply with a daily pill regimen.The development of alternatives for daily PrEP, and more adherence-friendly schedules, could increase prevention choices and increase acceptability. Because of the potential issue of adherence to a daily regimen, as well as the stigma issues around a daily pill regimen, an injection shot given once every two months, that would reduc...