Tokyo’s Covid-19 infections surged to a six-month high on Wednesday with the Olympic host city logging 1,832 new cases just two days before the Games open.
Tokyo is currently under its fourth state of emergency, which will last until August 22, covering the entire duration of the Olympics that start on Friday and end on August 8.
Fans are banned from all venues in the Tokyo area, with limited audiences at a few outlying sites.
“What we have worried about is now actually happening,” Japan Medical Association president Toshio Nakagawa said at a weekly news conference.
“The surge in cases has been expected whether we have the Olympics or not, and we are afraid that there will be an explosive increase in cases regardless of the Olympics.”
Experts noted that cases among younger, unvaccinated people are sharply rising as Japan’s inoculation drive loses steam due to supply uncertainty.
Many of the serious cases are those in their 50s.
Japan’s vaccinations began late and slowly, but the pace picked up dramatically in May for several weeks as the supply of imported jabs stabilised and prime minister Yoshihide Suga’s government desperately pushed to accelerate the drive before the Olympics.
About 23% of Japanese are fully vaccinated, still far short of the levels believed to have any meaningful effect to reduce risks on the general population.
Japan has had about 84,800 infections and more than 15,000 deaths since the pandemic began, most of them since the latest wave in January.
Experts on Wednesday warned that Tokyo’s infections would only worsen in coming weeks.
Dr Norio Ohmagari, the Tokyo metropolitan government’s expert panel member, said that Tokyo’s average daily cases could hit around 2,600 in two weeks if they continue at the current pace.
Mr Suga’s government has been criticised for what some say is prioritising the Olympics over the nation’s health.
His support ratings have fallen to around 30% in recent media surveys, and there is little festivity ahead of the Games.
Dr Shigeru Omi, the government’s top medical adviser, last week urged authorities to step up virus measures and asked people to avoid out-of-town trips.
International Olympic Committee president Thomas Bach, who is in Japan, expressed hope that fans would be allowed if the situation improves, but Dr Omi said that would be impossible.