Coronavirus live news: Chinese vaccine 50% effective in Brazil; US CDC expands pre-flight Covid testing

Employees handle vials containing CoronaVac, Sinovac Biotech’s coronavirus vaccine, in the bottle filling section at Butantan biomedical production center in Sao Paulo, Brazil 12 January 2021. Photograph: Amanda Perobelli/Reuters

source https://www.theguardian.com/world/live/2021/jan/13/coronavirus-live-news-chinese-vaccine-50-effective-in-brazil-us-cdc-expands-pre-flight-covid-testing