TOKYO—Initial data suggest that the spectator-free Tokyo Olympics didn’t exacerbate the Covid-19 outbreak in Japan, providing organizers of the Winter Games in China in February with one template for hosting the event.
Japan held the Summer Games from July 23 to Aug. 8 despite concern that around 50,000 athletes, officials and others from overseas might accelerate the spread of the virus. The visitors arrived mostly in July, just as the highly contagious Delta variant was hitting Japan with full force, and infections in the country hit a peak in the first part of August during the Games.
The scale and speed of infections in Tokyo were similar to the spread in other parts of Japan and other countries hit by Delta. While superspreading events in other countries have led to rising caseloads for weeks or months afterward, cases in Tokyo and in Japan overall fell sharply starting in mid-August and are now down to about a quarter of the peak.
“I think we can still say that these Games were safe because we have no indication whatsoever that there was any infection being transferred from the Olympic bubble to the people of Tokyo or to the people of Japan,” International Olympic Committee President
said last Thursday.
Tokyo Gov. Yuriko Koike
said Friday that she had reached the same conclusion because government data showed the pace of Delta’s spread slowed as the Olympics were happening.
Japan’s anti-Covid-19 measures during the Games included barring spectators from almost all events and requiring frequent testing of athletes and other participants. Visitors from overseas were told to restrict their movements to Olympic venues and use specially arranged vehicles to travel among them.
The athletes weren’t in a complete bubble. Hundreds of Japanese Olympic staff, contractors and volunteers traveled between Olympic venues and the local community throughout the 16-day Olympics and the subsequent 12-day Paralympics.
Some medical experts said it was too early to say whether the Games were safe. Organizers said 29 athletes and more than 500 other people involved in the event, including Japanese staff and visiting officials, were confirmed to have Covid-19 infections.
Dr. Annie Sparrow, an assistant professor in population health science at the Icahn School of Medicine at Mount Sinai Hospital in New York, said full genomic data about the infections would provide a better picture of how the virus was transmitted.
“There’s no way to understand or verify infection chains unless you do the sequencing and unless you actually publish that information,” Dr. Sparrow said.
“‘There was quite a well-controlled situation in the Olympic Village, but outside it was totally the opposite.’”
— Dr. Kenji Shibuya, a former director of the Institute for Population Health at King’s College London
A report by Japan’s National Institute of Infectious Diseases on Aug. 28 pointed to an Olympic connection in cases of Delta with a certain mutation. The mutation was associated in one study with the ability to escape antibodies. The report said 33 of 41 cases in Japan of this Delta type were found in people involved in the Olympics or Paralympics.
The findings leave open the possibility that Olympic visitors brought a new form of Covid-19 into Japan, although the institute said it didn’t see that mutation spreading further and that its impact isn’t known.
Dr. Kenji Shibuya, a former director of the Institute for Population Health at King’s College London, said there were no clear cases of transmission into the community from the Olympic Village, where most athletes stayed. Nonetheless, he said the Games couldn’t be considered safe because they took place when Japan had low rates of vaccination and testing.
“There seems to be a double standard here. There was quite a well-controlled situation in the Olympic Village, but outside it was totally the opposite,” he said.
One European delegation to the Olympics with athletes who tested positive for Covid-19 was told by officials in Tokyo that some of the infections originated in Japanese staff working at the Games, according to a person involved in dealing with the cases. The delegation was asked not to make the discovery public, the person said. The local Olympic organizing committee said there hadn’t been any confirmed cases of infections passing from Japanese staff to foreign visitors.
Beijing hasn’t said much about how it will conduct the Games, including whether spectators will be permitted and whether foreign visitors will be free to roam. Chinese Olympic officials have consulted with organizers of the Tokyo Games.
Dr. Sparrow, of Mount Sinai Hospital, said a tighter bubble than Japan’s was warranted, such as the one adopted by the Women’s National Basketball Association in the U.S.
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