As influenza cases rise, residents rush to get flu shots

Japan saw the average number of influenza patients jump to 11.35 per clinic for the week through Oct. 4, the health ministry said Friday, causing people to rush to get flu shots as an unusually early season hits the country.

The health ministry figure was about seven times higher than in the same period in 2025, which was 1.56. The latest numbers are up from 7.17 patients per monitored medical institution the week before.

The flu has been spreading rapidly particularly among children, with schools that closed classes rising sixfold week-over-week to 937.

The ministry declared the start of the flu season — or when there is a nationwide average of at least one patient per clinic in a week — on Aug. 28, the second earliest date since records began in 1999.

Dr. Shinya Ichimura, the head of Kawasaki Chuo Clinic, said that while there are many factors behind the early start to the flu season, one reason could be the increasing number of foreign tourists visiting from the Southern Hemisphere, where the winter season corresponds with Japan’s summer.

“There are diseases that aren’t present in the summer in Japan but are brought by people coming from places where it is already winter,” Ichimura said. “As it turns to fall and gets colder here, I believe that cases would increase. After all, the flow of people and human interaction has grown significantly.”

Ichimura posited several other hypotheses about the late-summer flu spike, such as cooler temperatures, the growing use of air conditioners that cool and dehydrate rooms, summer festivals that draw packed crowds and earlier back-to-school days for children.

As influenza surges, so too has the demand for earlier vaccinations. The health ministry notified local governments on Aug. 31 that they can start free vaccinations for the vulnerable population, including older people, earlier than the usual Oct. 1. Many local governments have started vaccinations earlier, with cities such as Urasoe in Okinawa Prefecture starting as early as Sept. 15.

While more people have been rushing to get their flu shot this year, people often wait until later in the season in the hopes of extending their immunity later into the winter. Others who have already gotten influenza may think about foregoing the vaccine altogether.

Ichimura, however, recommends that the earlier, the better.

“I personally believe that you should get vaccinated as soon as possible, but I know there are some people who try and time it, so it’s hard to say for certain when (it is most effective to get the flu shot),” Ichimura said. “But even if you have already had the flu, you should get vaccinated because your symptoms will be milder if you catch it again. So I do believe that people should get the flu shot early, and I always tend to get it early myself.”

In addition to vaccination, Ichimura reiterated common flu precautions such as thorough hand-washing, gargling and masking.

“That’s really about all there is. Those are the fundamentals.”