One widely shared list assembled 43 possible reasons cited in media reports, ranging from a culture of mask-wearing and a famously low obesity rate to the relatively early decision to close schools. Among the more fanciful suggestions include a claim Japanese speakers emit fewer potentially virus-laden droplets when talking compared to other languages.

Experts consulted by Bloomberg News also suggested a myriad of factors that contributed to the outcome, and none could point to a singular policy package that could be replicated in other countries.

Nonetheless, these measures still offer long-term lessons for countries in the middle of pandemic that may yet last for years.

An early grassroots response to rising infections was crucial. While the central government has been criticized for its slow policy steps, experts praise the role of Japan’s contact tracers, which swung into action after the first infections were found in January. The fast response was enabled by one of Japan’s inbuilt advantages — its public health centers, which in 2018 employed more than half of 50,000 public health nurses who are experienced in infection tracing. In normal times, these nurses would be tracking down more common infections such as influenza and tuberculosis.