He Jiankui, who was convicted of practicing medicine without a license, was also fined 3 million yuan ($430,000) by a court in the southern city of Shenzhen, China's official Xinhua News Agency reported. Two other researchers involved in the project received lesser sentences and fines.
The verdict said the three defendants had not obtained qualification as doctors, pursued fame and profits, deliberately violated Chinese regulations on scientific research, and crossed an ethical line in both scientific research and medicine, according to Xinhua. It also said they had fabricated ethical review documents.
The court also confirmed a third birth, saying the researchers were involved in the births of three gene-edited babies to two women. It said all three scientists pleaded guilty during the trial, which Xinhua reported was closed to the public because of privacy concerns.
He, the lead researcher, shocked the scientific world when he announced in November 2018 that he had altered the embryos of twin girls who had been born the same month. He described his work in exclusive interviews with The Associated Press.
The announcement sparked a global debate over the ethics of gene editing. He said he had used a tool called CRISPR to try to disable a gene that allows the AIDS virus to enter a cell, in a bid to give the girls the ability to resist the infection. The identity of the children has not been released, and it isn't clear if the experiment succeeded.
The CRISPR tool has been tested elsewhere in adults to treat diseases, but many in the scientific community denounced He's work as medically unnecessary and unethical, because any genetic changes could be passed down to future generations. The U.S. forbids editing embryos except for lab research.
He, who is known as "JK," told the AP in 2018 that he felt a strong responsibility to make an example, and that society would decide whether to allow the practice to go forward. He disappeared from public view shortly after he announced his research at a conference in Hong Kong 13 months ago, apparently detained by authorities, initially in an apartment in Shenzhen, a city in Guangdong province that borders Hong Kong.
It wasn't clear if the three-year prison term includes any of the time he has already spent in Chinese custody.
A Chinese scientist said the sentence should have been harsher to deter others. Kehkooi Kee, a Tsinghua University researcher who conducts gene-editing research on stem cells, also said that He should be held responsible for any fallout from the experiment on the lives of the babies and their families.
Dr. William Hurlbut, a Stanford University bioethicist whose advice He sought for more than a year before his experiment, said he felt sorry for the scientist, his wife and two young daughters.
"I warned him things could end this way, but it was just too late," Hurlbut wrote in an email addressed to the AP; the director of the U.S. National Institutes of Health, Dr. Francis Collins; and gene-editing pioneer Jennifer Doudna at the University of California, Berkeley.
"Sad story — everyone lost in this (JK, his family, his colleagues, and his country), but the one gain is that the world is awakened to the seriousness of our advancing genetic technologies," Hurlbut wrote.
Dr. Eric Topol, who heads the Scripps Research Translational Institute in California, noted it's almost unheard of for a scientist to get imprisoned "but in this case the sheer recklessness and unethical behavior warranted it." Topol praised China for standing up "for proper medical research conduct."
Doudna told the AP she was concerned about the "mysterious" legal process in China, but she said the sentences are "a step toward bringing this case to closure" and send a strong message to discourage other such work. (Doudna is paid by the Howard Hughes Medical Institute, which also supports AP's Health and Science Department.)
"As a scientist, one does not like to see scientists going to jail, but this was an unusual case," Doudna said. He's work was "clearly wrong in many ways."
Before setting up a lab at the Southern University of Science and Technology of China in Shenzhen, He studied in the U.S. The verdict accused him of colluding with Zhang Renli and Qin Jinzhou, who worked at medical institutes in the same province.
Zhang was sentenced to two years in prison and fined 1 million yuan, Xinhua said. Qin received an 18-month prison sentence, but with a two-year reprieve, and a 500,000 yuan fine.