Scientists at Stanford University and the Broad Institute of MIT and Harvard have for the first time used artificial intelligence to design entirely new, functional viruses — an achievement that experts are calling a significant turning point in biology, while also raising urgent questions about the safety of the technology.

The research, published in the journal Science, involved training AI models known as Evo1 and Evo2 on genetic codes drawn from viruses, bacteria, plants and humans. Working similarly to large language models that predict sequences of text, the models were used to generate thousands of genomes based on a naturally occurring bacteriophage — a type of virus that infects bacteria rather than humans — as a template. The team chemically synthesised 302 of the most promising AI-designed genomes in the laboratory. Sixteen proved viable, successfully replicating and killing E. coli bacteria more effectively than naturally occurring viruses.