Back-to-School Flu Visits May Exceed 100,000! Doctors Warn of 'Dual-Virus' Threat: Children's Infection Risk to Family Triples

In 2026, Taiwan has recorded 740 severe influenza cases and 137 deaths. Surveillance by the Taiwan Centers for Disease Control (CDC) shows repeated flu outbreaks in recent years, with a pattern of alternating A and B strains this season. Dr. Lee Ping-ying,理事长 of the Taiwan Vaccination Advocacy Association and attending physician in pediatric infectious diseases at National Taiwan University Children's Hospital, emphasized that young children are at high risk for severe flu complications. With flu and COVID-19 cases rising again and the September school reopening approaching, children may face dual infection risks from both influenza and SARS-CoV-2. He urges parents to vaccinate their children as soon as flu shots become available in October. In addition to traditional injectable vaccines, a needle-free nasal spray flu vaccine is available. Eligible children and adolescents can assess the most suitable vaccination method based on individual circumstances to reduce the risk of school-based outbreaks and severe illness.

Influenza is not just a common cold—severe cases carry a 16% fatality rate, with risks of encephalitis and myocarditis. Taiwan has entered a period of concurrent flu and COVID-19 circulation, exposing the public to a 'dual-virus threat.' A-type flu currently dominates, accounting for 89% of community flu cases according to recent CDC data. Statistics show that since autumn 2025, the A(H3N2) variant rapidly became Taiwan's dominant strain. In March 2026, B-type flu surged, peaking at around 69%. By June, A(H1N1) rebounded to 53%, indicating an alternating pattern of A and B flu circulation.

Dr. Lee recommends that high-risk groups—including preschoolers, adults over 65, and chronic disease patients—get vaccinated as soon as the flu vaccine rollout begins to reduce the risk of severe complications and death. According to the latest CDC flu vaccination program report (113), among those under 18, preschool children aged 3 and above have the lowest vaccination rate, with 14% having never received a flu shot. The danger of flu for children extends beyond infection itself—severe and fatal complications are a major concern. Most severe and fatal flu cases among children and adolescents under 18 in recent years involved individuals who had not received the seasonal flu vaccine. Data shows a 16% fatality rate among severe flu cases. The U.S. CDC's most recent flu season surveillance found that 18% of pediatric flu deaths (under 18) were due to influenza-associated encephalopathy or encephalitis (IAE).

Dr. Lee stressed that 'influenza is not just a common cold.' Beyond pneumonia, children are particularly vulnerable to severe complications such as encephalitis, encephalopathy, and myocarditis.

Children's infection risk is 5 times higher than adults—beware the 'school-to-family' transmission chain. CDC flu forecast data estimates that flu-related outpatient visits before school reopening could exceed 100,000. Studies show children are five times more likely than adults to contract flu outside the home. Over half of household flu transmissions can be traced back to infected children. Once a child is infected, the risk of infection among cohabiting family members may triple. Dr. Huang Yu-cheng,常务理事 of the Taiwan Vaccination Advocacy Association and consultant physician in pediatric infectious diseases at Linkou Chang Gung Memorial Hospital, warns that young children in daycare or after-school programs face high risks of cluster infections, easily creating a 'school infection, family transmission' chain.

Dr. Huang cited a clinical case of a 12-year-old boy who died from A-type flu. The boy developed high fever the day before returning home and suffered multiple seizures with loss of consciousness during a flight from Japan to Taipei. Upon landing, he was rushed to the hospital but was already comatose with dilated pupils. He was diagnosed with acute necrotizing encephalitis caused by A-type influenza and had never received a flu vaccine. Dr. Huang reiterated that flu progression in children can deteriorate rapidly. If warning signs such as rapid breathing, altered consciousness, excessive drowsiness, or reduced activity occur after infection, immediate medical attention is crucial to avoid missing the treatment window.

Dr. Huang noted that many children cry at the sight of needles, especially preschoolers. Taiwan introduced the nasal spray flu vaccine last year—a method used in Europe and the U.S. for over 20 years. Suitable for eligible children and adolescents aged 2 to 17, it is sprayed directly into the nasal cavity, triggering mucosal antibodies and forming a 'first line of defense' in the upper respiratory tract where viruses enter. The process takes only seconds, is painless, and provides comprehensive protection for both upper and lower airways. It also increases vaccination willingness among needle-fearful children, potentially boosting overall vaccine coverage. Numerous clinical trials have shown significant protective effects of the nasal spray vaccine in children. Regardless of vaccine type, flu vaccination provides protection for 6 to 12 months and reduces the risk of severe illness and death. Currently, Taiwan's government-funded flu vaccines are injectable only, while the nasal spray version is available at personal expense. Parents can consult local clinics or hospitals based on their child's needs to prevent chain transmission in schools, homes, and communities.