The country never imposed a rigid quarantine, and vaccination started late but then progressed at speed. The bars and transports are complete, but experts do not know why the contagion figures plummeted.
Almost overnight, Japan has become a striking - and somewhat mysterious - a coronavirus success story.
New COVID-19 infections have plummeted, from a peak of nearly 6,000 a day in Tokyo in mid-August to daily numbers below 100 in the populous capital, the lowest in 11 months.
The bars are packed, the trains are packed, and the mood is for celebration, despite widespread intrigued about what exactly caused the steep decline.
Unlike other countries in Europe and Asia, Japan never imposed anything close to strict quarantine, just a series of relatively mild emergency declarations.
Among the possible factors is a vaccination campaign that started late but has gained much speed, the fact that many areas of leisure night emptied by fear of contagion during the peak of summer, the widespread custom of using masks as before pandemic, and stormy weather in late August, which caused many people to stay home.
But the effectiveness of the vaccine is gradually reduced. With the approach of winter, experts fear that without knowing exactly why the infections have fallen so abruptly, Japan could suffer another wave like that of summer, when severe cases hospitals were overflowing, and deaths skyrocketed, albeit lower than before vaccinations began.
Many credit the vaccination campaign, especially among young people. Almost 70% of the population has completed their immunization. "The rapid and intensive vaccinations in Japan among those under 64 years of age could have created a temporary situation similar to herd immunity," said Dr. Kazuhiro Tateda, professor of virology at Toho University.
Tateda noted that the vaccination rate had grown between July and September, just as the most contagious delta variant was expanding rapidly.
However, he cautioned that post-vaccination infections in the United States, Britain, and other places where injections began months earlier than in Japan show that vaccines alone are not perfect protection and their effectiveness is gradually diminishing.
Japan started vaccinations in mid-February, with health workers and the elderly first. However, a lack of imported vaccines kept the campaign from gaining speed until the end of May, when supplies stabilized. Daily dose targets were raised to more than a million to maximize protection ahead of the Olympics, held July 23. and on August 8. The number of doses administered per day reached about 1.5 million in July, raising the vaccination rate from 15% in early July to 65% in late October, up from 57% in the United States.
New infections rose again a few weeks before the Games, forcing Japan to hold the Olympic event with 5,000 cases in Tokyo and about 20,000 across the country in early August. Tokyo reported 40 cases on Sunday, the ninth day in a row below 100 and the lowest number of the year. Across the country, Japan reported 429 new infections on Sunday, for a cumulative total of 1.71 million and 18,000 deaths since the pandemic's start early last year.
So why the fall?
"It is a difficult question, and we have to consider the effect of the progress of vaccinations, which is extremely large," said the director of the Center for Disease Control and Prevention, Norio Ohmagari. "At the same time, people who gather in high-risk environments, such as crowded and less ventilated places, may already have been infected and acquired natural immunity."
Although some speculated that the decline in cases could be due to less testing, data from the Tokyo metropolitan government indicated that the positive rate had dropped from 25% in late August to 1% in mid-October, while the number of diagnostic tests was reduced by a third. Masataka Inokuchi, deputy director of the Tokyo Medical Association, said the drop in positivity rates shows that infections have slowed.
The measures of the state of emergency in Japan were not quarantines. Still, requests focused mainly on bars and restaurants, which were asked to close soon and not serve alcohol. Nevertheless, many people continued to make daily trips on crowded trains and attend sporting and cultural events in stadiums with some social distancing measures.
The emergency recommendations have been withdrawn. The government gradually expands social and economic activity. It allows sports tournaments and group trips on a trial basis, with vaccination certificates and more diagnostic tests.
Former Prime Minister Yoshihide Suga, who recently left office, accelerated the vaccination campaign by expanding the number of health workers authorized to administer the injections, opened large vaccination centers, and promoted vaccinations in workplaces since the end of June.
The vaccinations would have helped keep 650,000 from becoming infected and saved more than 7,200 lives between March and September, Kyoto University professor Hiroshi Nishiura said at a recent government advisory committee meeting.
At first, many experts blamed the infections on young people, who were seen drinking on the streets and in parks when bars closed. However, the data showed that many people in their 40s and 50s also frequented the nightlife districts. In addition, the majority of severe cases and deaths were among unvaccinated people in their 50s or younger.
Takaji Wakita, director of the National Institute of Infectious Diseases, recently told reporters that he fears that people have already returned to nightlife districts, noting that the decline in infections may have bottomed out. "Going forward, it is important that we continue to reduce the number of patients in the event of a future spike in infections," Wakita said Thursday.
New Prime Minister Fumio Kishida said on Friday that the preparedness plan planned for early November would include stricter limits on some activities and require hospitals to provide more beds and staff to treat COVID-19 in case infections grow. To "the worst possible situation." He did not elaborate.
Regardless of the numbers, many people are reluctant to lower their guard. Wearing masks "has become very normal," said college student Mizuki Kawano. "I'm still worried about the virus," she said. "I don't want to go near those who don't wear masks," said her friend, Alice Kawaguchi.
The public health experts want a thorough investigation into why the infections have fallen.
An analysis of GPS data showed that the movement of people in prominent nightlife areas fell during the last state of emergency, which ended on September 30. " I believe that the decline in people visiting leisure areas, along with the progress of vaccination, have contributed to the decline in infections, " said Atsushi Nishida, director of the Research Center for Medical Sciences and Social Sciences at the Metropolitan Institute. Tokyo University of Medical Sciences.
However, people returned to the entertainment districts as soon as the state of emergency ended, he said, and that could "affect the infection situation in the coming weeks.