#19,312
Even though it is still August - and the Southern Hemisphere's flu season is still ongoing - Japan's Ministry of Health, Labour and Welfare today has announced an unusually early start to their fall flu season.
While primarily a fall/winter phenomenon, the Northern Hemisphere isn't entirely devoid of influenza in the summer. Hong Kong often reports both a winter and a summer flu season and has been reporting elevated activity (mostly H1N1) since mid-summer.
In Chinese Mainland (week ending Aug 16, 2026), the percentage of specimens that tested positive for influenza in the southern provinces slightly increased, while that in the northern provinces remained low, with the rates at 18.6% and 2.1% in week 33, respectively. The proportion of influenza A(H3N2) among detections increased nationwide. In Macao (week ending Aug 15, 2026), the influenza positivity rate was 20.9%, which was higher than the alert level. Influenza A (H3) was predominating.
While Japan's flu season normally begins in November or December, last year it kicked off in early in early October, with the arrival of the drifted subclade K H3N2 virus.
While it is too soon to even begin to guess about the severity - or longevity - of this year's flu season, Japan is urging its citizens to take prevention seriously. The following (translated) excerpt comes from today's press release.
[Basic Infection Control Measures] Effective ways to prevent infectious diseases, including influenza, are "handwashing" and "cough etiquette , including wearing a mask ."
In particular, the risk of developing severe symptoms increases for the elderly and those with underlying medical conditions. When meeting with the elderly, going to the hospital, or gathering in large groups, please cooperate with infection control measures, including wearing a mask.
[Situations where wearing a mask is effective] To prevent infection among the elderly and other people at high risk of severe illness, wearing a mask is recommended when visiting a medical institution or when visiting medical institutions or elderly care facilities where many elderly people and other people at high risk of severe illness are hospitalized or living . In addition, during influenza season, when people at high risk of severe illness go to crowded places, wearing a mask is an effective measure to protect themselves from infection.
Attachment This outbreak is the second earliest since the Infectious Diseases Control Law was enacted in 1999, following 2009*, and last year...
[Vaccination] The influenza vaccine is believed to have some effect in suppressing the onset of the disease and preventing severe illness, and is considered to be particularly effective for the elderly and those with underlying medical conditions, who are at high risk of developing severe illness if they contract the disease. The following people are eligible for routine vaccination: ÿ People aged 65 and over ÿ People aged 60-64 with impaired heart, kidney, or respiratory function that severely restricts their daily life , or people with impaired immune function due to human immunodeficiency virus (HIV) that make daily life almost impossible. These people can receive one dose of influenza HA vaccine as part of routine vaccination. In addition, the influenza vaccine and the COVID-19 vaccine can be administered on the same day. Please consider getting vaccinated together with the COVID-19 vaccine. We would appreciate your cooperation in spreading this information to the media.
(Reference) Summer Infectious Disease Control Measures | Ministry of Health, Labour and Welfare Phone number: 0120-995-956 Reception hours: 9:00 AM - 5:00 PM, Monday to Friday (excluding public holidays and year-end/New Year holidays) According to the infectious disease surveillance data for the 34th week of 2026 (August 17th to August 23rd), the number of reported influenza cases per sentinel site was 1.11 (number of sentinel sites: approximately 3,000 nationwide, number of reported cases: 4,094).
Since this exceeds the threshold of 1.00 used as the benchmark for the start of an epidemic, it is believed that the influenza season has begun again this year. We have opened a consultation service for infectious diseases and vaccinations, including influenza . Please feel free to use it. *The telephone number changed on April 1, 2025
Every flu season is different, and as we've seen many times, flu seasons can vary widely around the world, making it unknowable if this early arrival will be duplicated in North America or Europe.
While I generally like to wait until October to get my seasonal flu shot, if this trend continues, I expect I'll be rolling up my sleeve a little earlier this year.
