• In this Oct. 10, 2018 photo, He Jiankui speaks during an interview at a laboratory in Shenzhen in southern China's Guangdong province (AP)

Scientist He Jiankui who worked on the world’s first gene-edited babies was found guilty of “illegal medical practices,” and received a three-year prison sentence has said he moved “too quickly” with the procedure.

When the scientist announced in 2018 that he had edited the genes of twin girls, Lulu and Nana, before birth, the world of science was shocked. After his announcement, his university in Shenzhen dismissed him, and he received a prison sentence and was widely condemned for having proceeded with the risky, ethically controversial, and medically unjustified procedure, especially that he received no adequate approval from the families of the twin girls.

In one of his first interviews since his public re-emergence last year, he told The Guardian: “I’ve been thinking about what I’ve done in the past for a long time. To summarise it up in one sentence: I did it too quickly.”

He refused to give more information on what he believed needed to have happened before going ahead with gene editing, saying he would give more details at an invited talk he is scheduled to give next month at the University of Oxford.

He Jiankui majored in physics in China before moving to the United States to pursue a Ph.D. at Rice University and a post-doctorate in genome sequencing at Stanford University. In 2012, he went back to China to pursue Crispr-Cas9 gene-editing research, launching a variety of biotechnology business ventures.

At the time, gene-edited cells were already starting to be used for adults in clinical treatments. However, gene editing for embryos was and still is far more ethically contentious, as changes are made to every cell in the body and are passed down to subsequent generations. Critics even have questions on whether such a step could ever be medically justified.

Four years ago, He Jiankui dropped the bombshell at an international conference in Hong Kong, announcing he had modified two embryos before they were even placed in their mother’s womb. Later, it emerged that a third gene-edited baby had been born.

The edit of a gene called CCR5 targeted a pathway used by the HIV virus to enter cells, and allegedly gave babies immunity to HIV.

Some of the unpublished data show concerning proof of “off-target” effects, unwanted genetic changes that can have heart defects risk factors, in addition to cancer and developmental problems.

He Jiankui says he had kept contact with the twins’ family, but does not give details about whether he took part in their clinical follow-up or whether he saw them recently.

“Lulu and Nana are living a normal, peaceful, undisturbed life and we should respect them,” he said. “We respect patient privacy and, for me, I put the happiness of the family first and the science discovery second.”

When asked about how the third child was doing, he refused to answer, saying later that the child was “living a normal life living with their parents”.

He seems to have intentions to relaunch his career, and he does not consider the scandal as an insurmountable barrier to running clinical trials again in the future.

He has set up a lab in Beijing to work on affordable gene therapies for rare diseases such as Duchenne muscular dystrophy. According to him, he has secured enough funding through donors to rent lab space, hire five scientists and start animal studies. He even says he will use his own wealth if needed to take the venture further.

He is scheduled to give an online seminar on bioethics next week at the University of Kent.

“According to Chinese law, when a person has served the prison [sentence], after that they begin again with full rights,” he said. “Compared to the past experience, it’s more important what we’re doing today that determine whether I move on or not.”

It is worth noting that a South Korean scientist, Hwang Woo-suk, became internationally infamous in 2006 after creating a human cloning breakthrough and using eggs donated by his students, but went back to scientific research on pig cloning and commercial ventures cloning pets and farm animals.

He might be able to move on, but the three children will continue to carry the changes he made to their DNA, with uncertain health consequences.