The lockdown in the Chinese outbreak city of Wuhan brought the COVID-19 epidemic crashing to a halt, giving health systems crucial breathing room to deal with serious cases, new research showed Thursday.

Chinese authorities ordered schools, universities and businesses shut following a cluster of COVID-19 cases in the transport hub in January, confining millions of people to their homes in a bid to contain the outbreak.

The measures sent the numbers of new cases tumbling, and parts of Hubei province, where Wuhan is situated, have slowly started returning to normal.

With roughly three billion people currently advised to stay at home amid the pandemic, a study published in The Lancet Public Health examined what the rest of the world can learn from Wuhan.

Researchers developed a model to estimate the impact that school and business closures had on COVID-19 transmission rates, using data on how often people interact and where.

The Wuhan outbreak came at the worst possible time — on the eve of Lunar New Year, when tens of millions of Chinese travel to celebrate with their families.

The study compared three separate scenarios: no intervention and no holiday travel; no physical distancing and normal holiday travel; and school closures with only key workers at work.