Robert Grant, a virologist at the University of California, San Francisco (UCSF), who was not involved in the study, believed that the new study "would be a game changer". "This is the most exciting thing happening that I know of in HIV prevention studies today," Grant, a pioneer of oral PrEP studies in humans, told the Science journal. Philip Johnson of the Children's Hospital of Philadelphia in Pennsylvania, however, questioned the compliance. "This is going to require multiple injections over the lifetime of an individual," Johnson told Science. "How feasible is it truly in the long term?"

Ho said while HIV vaccines that protect are "still far far away", their approach could be used in the interim period before a protective vaccine is developed. He said their next step is to proceed, together with drugmaker GlaxoSmithKline, to conduct human trials. "We will soon begin a phase-2 human trial of 744LA in the U.S. It is anticipated that we will obtain more data, including more safety information, on this long-acting drug within the next year," he said. "We are now in discussion with the company on how to ultimately proceed with clinical trials to test the protective efficacy of 744LA in high risk populations throughout the world, including in gay men in China where HIV infection rates are very high."

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