The computer did not create a virus. It did not touch a test tube or handle a living cell. What it did may ultimately be more consequential: it helped decide what the virus’s genome should be.

Researchers at Stanford University and the Arc Institute used artificial intelligence (AI) to design complete genomes of bacteriophages - viruses that infect bacteria. Of 285 AI-generated designs physically synthesised and tested in the laboratory, 16 produced functioning phages. Some were able to overcome bacterial resistance that defeated the original virus. The phrase ‘AI-created viruses’ therefore needs qualification. Humans have been synthesising viral genomes and deliberately modifying viruses for decades. What is new, is not the physical manufacture of a virus. AI has entered the design stage of biology. For medicine, that creates remarkable opportunities. For biosecurity, it raises equally important questions.