One problem with CRISPR editing is that it sometimes introduces mutations far from the gene at which it is aimed at correcting.
If confirmed, the feat would be the first of its kind - and ethically controversial.
The claims come ahead of a conference of world experts in Hong Kong on Tuesday, where He is expected to reveal more details. "Society will decide what to do next" in terms of allowing or forbidding such science.
Doudna, a scientist at the University of California, Berkeley and one of the Hong Kong conference organizers, said that He met with her Monday to tell her of his work, and that she and others plan to let him speak at the conference Wednesday as originally planned.
Zhang Linqi, a professor at Tsinghua University who specializes in HIV treatment, said that He's gene-editing experiment using healthy embryos is "unwise and unethical".
"The human genome belongs to all of us and in some sense we all get to have a say", Baylis added.
George Church, from Harvard, however, defended this research.
"If this was done to avoid HIV infection, there are alternative ways to prevent infection that are already effective", Doudna says, such as "washing" the sperm of infected sperm donors to eliminate HIV.
"Not only do I see this as risky, but I am also deeply concerned about the lack of transparency", said Zhang, a scientist at MIT's Broad Institute.
In addition, Annas wrote, He focused on "a disease (susceptibility to HIV infection) that virtually no one things should be "cured" by gene editing (since it is both preventable and treatable by current practices)". He used a powerful new gene editing tool called CRISPR-cas9, which has the ability to rewrite DNA, according to the report.
He, who created two companies based on his studies, is scheduled to present his findings at the Second International Summit on Human Genome Editing, and will certainly be the target of numerous questions from the leading gene-editing scientists in attendance. He has even applied for patents for some of his methods as a result of his study. "This suggests that the research of gene editing in China not only has a promising potential, but also is responding to the public's needs". As to how exactly JK has gone about it, he says that he sought to disable the CCR5 gene.
The team led by Jiankui He focused on removing a gene called CCR5, critical for the HIV virus to enter into the cells. He worked with seven heterosexual couples in which the male partner was HIV positive and the women were HIV negative.
In a first, genetically edited babies have been welcomed by the world.
In a pre-recorded video on the conference's website, biologist and chair of the worldwide summit David Baltimore said: "We have never done anything that will change the genes of the human race, and we have never done anything that will have effects that will go on through the generations". First, sperm was "washed" to separate it from semen, the fluid where HIV can lurk.
Subsequently, a single sperm was put into a single egg in order to create an embryo.
In recent years scientists have discovered a relatively easy way to edit genes, the strands of DNA that govern the body. At this point, couples were told that they could choose whether to use edited or unedited embryos for their pregnancy attempts.
The criteria under which heritable genome-editing clinical trials could be deemed permissible have been the subject of much debate and discussion by many research groups. Eleven edited embryos were then used in six implant attempts before one of the couples were able to achieve the twin pregnancy, He said. "We also do not need gene editing to ensure it isn't passed on to offspring", she said.
In general, those with one copy of the gene can still contract HIV, but there are chances that their rate of decline, when it comes to health could happen more slowly if they do.
Several scientists reviewed materials that Mr He provided to the AP and said tests so far were insufficient to draw conclusions.
The concept of genetically modified embryos is highly controversial due to the potential risks to the human and future generations.