Many pandemic viruses emerged naturally – but there’s one that most likely came from a lab

Most pandemic viruses that have jumped from animals to humans do not show signs of special adaptations to infect people, except the 1977 influenza outbreak, which was likely “sparked by a laboratory strain”, according to a new study.

Until now, such zoonotic viruses, which jump to humans from wildlife, have been assumed to first acquire mutations that enable sustained human-to-human spread.