2018 has seen a lot of great inventions and milestones, but this recent one made by a Chinese doctor is a historic scientific breakthrough that doesn’t happen all the time.

A Chinese scientist is claiming to have successfully altered the DNA of twin girls in such a way that they can never get AIDS, reported IndiaTimes. In a recently posted YouTube video, the doctor himself explains the methods he used and the family he was helping. To make this possible, the doctor used CRISPR gene-editing technique, a controversial gene-editing technique, to alter only the DNA that allows HIV to be contracted in humans.

This is a major milestone in the AIDS story. 

Sometime in the 1920s, it was widely believed that the AIDS virus, HIV, had spread from chimpanzees to human beings. It would be around 60 years before the first cases of AIDS would be reported amongst the homosexual community in Los Angeles, New York and San Francisco.

While the LGBTQ community faced the brunt of the virus, two years later in 1983, it was determined that the disease could also be transmitted through heterosexual intercourse after women were recorded having the disease.

The Princess of Hearts, Diana, opened the first HIV ward in a British hospital and was also photographed holding hands with an AIDS patient, reports Reuters. Given her stature and the level of public admiration she commanded, this aided in helping reduce the stigma. Freddie Mercury shocked the world in 1991 when he announced that he had the disease, a day before dying of pneumonia.

In 2012, oral prophylactic drug PrEP was approved and it has done wonders in preventing sexual transmission of the HIV virus.

Going back to the news mentioned in the first paragraph, in CRISPR, external protein along with some instructions is injected in the DNA, that will permanently prevent the twin girls — Lulu and Nana — from ever getting infected by HIV virus and contracting AIDS disease. A form of “cellular surgery” was performed on the two fertilized embryos.

In a report by Associated Press, the doctor fertilized the embryos for seven other couples through IVF treatments, and only one of those seven pregnancies has reportedly been successful. 

The doctor also explained how the father of the twins has HIV and through the gene surgery he performed on the twins, they will never contract HIV. 

“We heal a whole family. As a father of two girls, I can’t think of a gift more beautiful and wholesome for society, than giving another couple to start a loving family,” said the doctor.