When Paul initially saw the advertisement in April 2017—offering free experimental fertility treatments to HIV-positive men—he suspected that it was an internet scam. A Chinese law prohibits fertility clinics from offering services to people with sexually transmitted diseases. So he thought that these “scientists” might just be trying to take his money. Taking a gamble, he decided to share his contact details with the researchers via WeChat. As fate would have it, Paul and his wife became the first participants in Dr. He's research project. They signed up because they wanted a baby and they supported one of the big project goals: a cure for HIV.

News of the experiment had come from a trusted source: China's largest mutual aid organization for HIV-positive people, Baihualin, or White Birch Forest. More than 50,000 people, mostly gay and bisexual men, follow this group's WeChat account.

Around 300 people responded to the initial WeChat ad, including Paul (a pseudonym I’m using to protect his identity). The laboratory staffsent them a basic survey but did not initially reveal much about the details of the experiment. Paul responded to simple questions: What is your age? Are you married? What is your highest level of education? Are you or your partner infected with HIV? They also asked: Would you be interested in learning more about a new gene therapy that could reduce your children's risk for becoming infected with HIV?

The laboratory was looking for married couples with an HIV-positive man and an HIV-negative woman. They wanted to find people with university degrees, as Dr. He wanted to ensure that participants had enough educational background to have a basic understanding of science. Within days of the initial advertisement about the experiment, the laboratory was overwhelmed by volunteers.

After texting with the couples over WeChat, Dr. He's stafffollowed up with phone calls. They zeroed in on twenty eligible couples who seemed like the best fit. Then two researchers, an embryologist named Dr. Jinzhou Qin and a postdoctoral researcher who studied monkeys, packed their bags and started traveling around China. They visited the potential experimental subjects in their own homes.