https://www.siliconvalley.com/2021/12/30/covid-travelers-infected-one-another-across-hallwayresearch-shows/

(CNN) — A traveler isolated for Covid-19 at a quarantine facility in New Zealand managed to infect three others across a hallway, researchers reported Thursday.

Closed-circuit camera footage, genetic testing and careful contact tracing show that the only conceivable way the virus could have passed from one room to another was in air that leaked out when both doors were briefly opened, the researchers said.