Using CRISPR to Edit Eggs, Sperm, or Embryos Does Not Save Lives

The startling announcement by He Jiankui almost one year ago that he had created the first genetically modified human beings unleashed a torrent of criticism. It also brought to the surface common misunderstandings — even among scientists and ethicists — that reproductive uses of this genome-modifying tool have therapeutic value, will treat people with genetic disorders, will save lives, and will eradicate disease. None of those are true.

The twin girls that He helped create are publicly known as Lulu and Nana. Their father is HIV-positive. The scientist said he used CRISPR-Cas9 genome editing technology to disable a gene called CCR5 to mimic a naturally occurring gene deletion that appears to confer immunity against HIV.

A major criticism from the scientific community, which has otherwise been generally supportive of advancing gene technologies, was that He did not use the technology to address a serious medical need. That criterion stems from a 2017 report by the U.S. National Academy of Sciences and the National Academy of Medicine recommending that, once the technology is ready and safe, genetic modification of embryos could...