Days after a 17-year-old girl tested positive for COVID-19 in a remote part of western
China last week, health authorities said they had tested over 4.7 million people in the region.
China's strict formula of immediate lockdowns and mass testing even at the first signs of infection has been vital to its success in controlling the disease, allowing its
economy to quickly recover from the crisis, officials say.
The highly orchestrated strategy - described as "overkill" even by its own proponents - is unique among major economies at a time when Europe and the
United States are facing a massive surge of new cases and often chaotic policies.