China tests entire city for virus as WHO slams herd immunity idea

China rushed Tuesday to test an entire city of nine million within days after a minor coronavirus outbreak, as the WHO warned that letting the pathogen run free to achieve herd immunity was “scientifically and ethically problematic”. “Herd immunity is achieved by protecting people from a virus, not by exposing them to it,” WHO chief Tedros Adhanom Ghebreyesus said Monday, describing the idea as “scientifically and ethically problematic”.