Across the globe, a surge in seasonal influenza cases is sending ripples of concern through public health systems, with the 2025-2026 flu season shaping up to be one of the most challenging in recent memory. From Central Asia to Europe and East Asia, countries are grappling with rising infection rates, overwhelmed hospitals, and a flu virus that’s proving difficult to predict and control. At the heart of this season’s outbreak is a familiar but formidable adversary: the influenza A (H3N2) Hong Kong strain, which is dominating case numbers and prompting urgent responses from health officials everywhere.
In Kazakhstan, the Health Ministry’s Sanitary Epidemiological Control Committee has reported a sharp increase in flu cases, with 1,790 laboratory-confirmed infections as of December 1, 2025. According to The Caspian Post, nearly every region except Ulytau has been affected, and the vast majority of cases are due to the A (H3N2) Hong Kong strain. Children under 14 represent a staggering 58% of these cases—1,039 young patients—while pregnant women account for another 8.6% (155 cases). The government’s message is clear: limit social gatherings, wear masks when appropriate, spend more time outdoors, boost vitamin intake, and maintain a healthy diet to reduce the risk of infection.
Kazakhstan’s annual flu vaccination campaign is in full swing, with over 2.2 million people already vaccinated using a World Health Organization (WHO)-recommended formula that includes A (H1N1pdm09), A (H3N2), and B/Victoria strains. This proactive approach is echoed in other countries, but the effectiveness of the vaccine is being put to the test by the rapidly evolving virus.
Vietnam, too, is feeling the impact of the flu season. The Ministry of Health has sounded the alarm, warning citizens not to self-medicate with antiviral drugs such as Tamiflu without a doctor’s prescription. This caution comes amid a dramatic rise in seasonal flu cases—over 132,000 since the start of 2025, with three reported deaths, as noted by SGGP. The main strains in circulation mirror the global pattern: A/H1N1, A/H3N2, and influenza B. Children are particularly vulnerable, with influenza A infections among young patients jumping from around 400 cases in September to more than 4,000 by November, many requiring hospitalization due to complications.
The demand for Tamiflu in Hanoi has skyrocketed, leading to shortages and price hikes at pharmacies, where a box of ten capsules now costs between VND750,000 and VND850,000. Social media and online forums have become alternative marketplaces, with prices slightly lower, but the Ministry of Health continues to stress the importance of medical supervision to prevent misuse and drug resistance. Good personal hygiene, mask-wearing in crowded places, and prompt medical attention for symptoms are being strongly recommended.
Japan is experiencing what local authorities describe as the fastest pace of influenza infections in the past decade. The outbreak began earlier than usual, at the end of September, and by late November, approximately 200,000 new cases were reported in a single week from around 3,000 medical institutions nationwide—an average of 51 cases per facility, well above the alert threshold. According to Japanese media, the currently circulating virus is a derivative of the type-A Hong Kong strain, which has also been detected frequently in Southeast Asia and Europe since the summer. The importation of the virus is believed to be linked to increased foreign visitor numbers and heightened human movement.
Several factors are contributing to Japan’s predicament. The country’s stringent infection prevention measures during the COVID-19 pandemic reduced exposure to pathogens, resulting in a larger population with weakened immunity to influenza. The rapid drop in temperatures after an unusually hot summer has also left many, especially the elderly, more susceptible to illness. In the Saganoseki district of Oita, a cluster of cases was reported at an evacuation shelter for fire victims, highlighting the virus’s high transmissibility and the challenges of outbreak prediction in the post-pandemic era.
Japan’s response includes the introduction of new vaccine types, such as a nasal spray "painless vaccine" recommended by the Japan Pediatric Society for children, alongside the traditional injectable option. Public health officials are urging the population to adhere to basic precautions—mask-wearing and frequent handwashing—to prevent healthcare systems from becoming overwhelmed, and to protect schools and workplaces from disruption.
Meanwhile, in Scotland, laboratory-confirmed flu cases jumped by 45% in the week ending November 23, 2025, rising from 555 to 805, according to BBC Scotland. Hospital admissions increased from 279 to 391, and test positivity soared from 11.0% to 15.8%. All age groups are being affected at levels not previously seen this time of year. Dr. Victoria Shotton, a Glasgow-based GP, told BBC Radio Scotland, “We are seeing a massive increase in presentations on a daily basis. It has started early this year and is more severe than last year.” She added that “this year’s jab isn’t offering the same protection as last year” due to a new mutation in the circulating strain, but emphasized that vaccination still offers important protection against severe illness.
In the NHS Greater Glasgow and Clyde region, cases rose by 18% in just one week, and hospitals are feeling the strain. Some wards in Dumfries and Galloway have closed to new admissions due to concurrent outbreaks of flu and norovirus, and face masks have been reintroduced for staff and visitors. Health officials are urging the public to avoid visiting hospitals and care homes if feeling unwell, as even mild symptoms can have serious consequences for vulnerable populations.
Dr. Kenneth Donaldson, medical director for NHS Dumfries and Galloway, appealed for public cooperation: “We are currently seeing a significant increase in both respiratory and gastrointestinal infections across the region. Seasonal flu has arrived early this year, and we are also managing a rising number of norovirus outbreaks. These illnesses are circulating widely in the community and are now having a major impact on services.”
Symptoms that warrant medical attention include difficulty breathing, severe chest pain, vomiting, and diarrhea. Health Secretary Neil Gray stressed the importance of vaccination for those eligible, calling it “the best way that we protect ourselves from flu.”
The World Health Organization’s surveillance data for the 2025-2026 season reinforces the urgency of these national responses. Influenza virus activity is increasing globally, with the A/H3N2 strain dominating in Northern Europe, West Asia, South Asia, and Southeast Asia. The convergence of earlier-than-usual outbreaks, the dominance of a highly transmissible strain, and variable vaccine effectiveness has created a perfect storm for public health authorities.
As winter deepens, the message from health officials worldwide is one of vigilance and cooperation. Vaccination, personal hygiene, mask-wearing, and timely medical care remain the cornerstones of defense. With flu season far from over, these efforts will be crucial in protecting vulnerable populations and preventing healthcare systems from being pushed to the brink.
