Japan’s long-standing success in managing the pandemic was underpinned by extensive mask wearing, widespread vaccination, an already-healthy population and easy access to healthcare.

“The number of infected people will likely increase at a faster pace than in other countries from now on,” Ohmagari said. “Japan is a super-ageing society, which means the proportion of people with a greater mortality risk is high. In the long run, it’s possible that Japan will be among the countries with high mortality rates.”

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Japan is one of the fastest-ageing societies in the world, with people older than 65 making up 29 per cent of the 125 million population. The group is among the highest-risk for Covid, with reports that many deaths during the current wave have occurred among those with underlying conditions such as Alzheimer’s and heart disease.

The about-turn in Japan reflects the ongoing devastation wrought by the virus even as the world, including previous holdouts like China, resume pre-pandemic life.

While mainland China’s abrupt abandonment of zero-Covid in early December unleashed a wave of infections that contributed to a recent uptick in the global death rate, the figure was relatively stable for most of 2022.

The health system structure likely exacerbated the toll. Japan classifies Covid as a serious disease, much like tuberculosis or bird flu, and sends patients to specialised facilities equipped to handle it.

The designated Covid hospitals were overwhelmed by the rapid increase of patients during the wave that started in October and turned patients away, said Kenji Shibuya, an epidemiologist at the Tokyo Foundation for Policy Research.

Thousands of emergency patients were denied care by hospitals three times or more since the outbreak began, with the figure hitting a record 8,161 the week of January 9, according to the Fire and Disaster Management Agency.

“The number of emergency transports by ambulance increased, placing a heavy burden on designated hospitals already lacking manpower as medical professionals also got infected,” Shibuya said. “Communities can’t respond quickly enough to elderly people whose underlying conditions worsened because of Covid,” he said, calling for the classification to be quickly changed so more hospitals can treat the infected.

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There have been calls to downgrade Covid’s classification, and treat it like influenza, for more than a year. But the government has resisted, despite the signs that the cautious approach meant to control the spread of the virus is now contributing to making the death toll worse. A key political consideration is to avoid passing on costs to patients – if the classification is downgraded, people have to pay for treatment themselves like for other illnesses.

Covid measures still linger everywhere in Japan. Most people wear masks outdoors, hotels check temperatures and restaurants continue to place plastic sheets between tables. How they adjust to the reopening will determine the coming infection and death rates, health experts said.

“Our future depends on how elderly people protect themselves and if other people cooperate,” Ohmagari said. “I sincerely hope that there will not be a division in the society.”