The change applies to those who have an undetectable viral load.
The study came from a clinic based in the heart of London's gay scene.
Johnson & Johnson's attempted vaccine didn't have the efficacy necessary for the study to continue.
The U.N. has urged countries to immediately prioritize providing necessary, life-saving treatment.
Previous small studies found no elevated risk in people living with HIV. The World Health Organization says those were incorrect.
The first global study of syphilis in MSM finds high prevalence that the World Health Organization calls unacceptable.