observational and epidemiological studies, some physicians have long believed that HIV-infected individuals who receive antiretroviral treatments (ART) pose a lower risk of transmitting the virus to their sexual partners. 

In order to establish whether this was in fact true, researchers designed a randomized clinical trial to evaluate whether immediate versus delayed use of ART by HIV-infected individuals would reduce transmission of HIV to HIV-uninfected partners and potentially benefit the HIV-infected individual as well., 

what are the risks in this study? Explain Biefly?