Japan is confronting a severe influenza outbreak that has led to more than 6,000 hospitalisations and the closure of over 200 schools, prompting international concern about the risk of a new pandemic with winter fast approaching. The country’s Ministry of Health, Labour and Welfare (MHLW) announced on October 3 that the country had entered the flu season – the second-earliest start in two decades, arriving five weeks earlier than in 2024.
Cases jumped to 6,013 in the week to 5 October – a 50% increase from the previous week – surpassing the epidemic threshold of one patient per medical institution. Since early September, infections have totalled more than 20,000, with 75 deaths recorded, mainly among the elderly and children under five. The H3N2 strain, which often causes high fevers and respiratory complications, is predominant, and experts attribute the surge to weakened immunity after Covid-19, changing climate patterns and increased international travel.
Professor Yoko Tsukamoto of Hokkaido University of Health Sciences, pointing to how travel facilitates viral changes, said: “The flu season has started really early this year, but in the changing global environment this might become a more common scenario.”
Similar early outbreaks in Australia and Malaysia suggest a shift towards year-round transmission.
Alarm is spreading on social media, with users drawing parallels to the Covid era. One X post asked: “New pandemic coming? Japan declares nationwide flu outbreak, over 4000 hospitalised,” citing a fourfold rise in hospital admissions and more than 135 school closures by 3 October.
Another noted: “Reports indicate that Japan is experiencing the flu season about five weeks earlier than normal, raising concerns about changes in the behaviour of the virus in post-pandemic world.” Across Japan, 28 of 47 prefectures have surpassed epidemic levels, placing particular pressure on children’s wards.
In its October 10 update, the MHLW called for measured responses amid the rise: “Everyone should take preventive measures such as hand-washing and vaccination.”
It recommended that visitors wear masks in crowded areas and wash hands often, while expanding free vaccinations for older people and vulnerable groups – though participation stands at around 40 per cent, affected by fatigue from the pandemic years.
A full-scale outbreak is likely to occur around late December to February, according to the MHLW, which emphasises that there is no need for panic.
Prof Tsukamoto stressed the need for targeted protection, saying: “For most healthy individuals, the flu may be unpleasant but not dangerous. But for vulnerable groups, early vaccination is crucial.
“People need to take common-sense precautions, get vaccinated, wash hands regularly, and avoid spreading infection.”
With stockpiles of antivirals such as Tamiflu being increased and additional staff mobilised, the US Centers for Disease Control and Prevention is observing without issuing warnings, though specialists warn that Japan’s situation could spread further afield.
This outbreak does not yet resemble the events of 2020 and Covid.
However, as cases continue to double each week, Professor Tsukamoto’s advice carries weight: in an interconnected world, one country’s flu crisis could ignite a wider one. Vaccination, masking and basic hygiene remain essential.