Highlights from the 21st CROI

No virus, no risk? “Our best estimate is it’s zero”, said Alison Rodger when asked what the risk was of a person with undetectable viral load passing HIV onto a sex partner. Rodger and colleagues presented the PARTNER study (abstr 153), which enrolled serodiscordant couples who had sex without condoms, in which the infected partner was on antiretroviral therapy (ART) and had a viral load of less than 200 copies per mL. Among 757 couples (282 men who have sex with men), 894 couple years of followup, and almost 45 000 sex acts without condoms not one phylogentically linked HIV transmission occurred. Any acquired infections seemed to have been transmitted during extrapartner sex. The study is ongoing, and Jens Lundgren told press that he hoped that by 2017 they would have suffi cient data to confi rm zero risk of transmission, having recruited an additional 450 couples of men who have sex with men across 75 clinics in Europe.