Hong Kong’s Centre for Health Protection (CHP) issued a renewed, urgent plea to parents to vaccinate their children against seasonal influenza following the confirmation of a severe pediatric case involving an 11-year-old girl. The young patient, who recently arrived from overseas and had underlying health issues, was diagnosed with severe Influenza A complicated by encephalopathy after presenting with fever, cough, and confusion on December 1st, underscoring the persistent threat of the virus even as overall local activity fluctuates.
The girl, who entered Hong Kong on November 20th, was admitted to the Queen Elizabeth Hospital’s Accident and Emergency Department immediately after symptom onset. Laboratory tests confirmed the presence of Influenza A (H3), leading to the serious diagnosis. While her condition was initially critical, officials report she has since stabilized and remains hospitalized for monitoring. Critically, the child had not received the 2025/26 seasonal influenza vaccine, and her usual household contacts currently show no symptoms.
Unvaccinated Patients Dominate Severe Cases
This new case brings the total number of severe pediatric influenza infections recorded in Hong Kong during the current summer influenza season to 25, resulting in three tragic fatalities. Affected children span an age range from six months up to 17 years.
A significant concern highlighted by the CHP is the low vaccination rate among severe cases reported since the current immunization programs launched. Out of the 16 specific severe cases documented since the start of the vaccination period, only one child had been immunized. Furthermore, this single vaccinated patient developed symptoms just four days post-vaccination, insufficient time for the body to build protective immunity, which typically requires approximately two weeks.
Flu Threat Remains High Despite Easing Activity
Although local influenza activity saw a decrease in late October, the CHP notes the virus circulation remains above the seasonal baseline and warns of potential resurgence, particularly as winter temperatures begin to drop. This pattern mirrors an elevated or sustained influenza threat across many parts of the Northern Hemisphere, stressing the importance of early immunization, especially for residents planning international travel. Vaccinating promptly ensures adequate time for antibody development before potential exposure.
The seasonal influenza vaccine is strongly recommended for high-risk demographics, including pregnant women, older adults, children, and individuals managing chronic health conditions.
Key Public Health Recommendations
The CHP strongly advises the public to adopt preventive measures and seek timely medical assistance if respiratory symptoms arise.
Actionable Takeaways:
- Vaccinate Immediately: Parents must arrange the free seasonal influenza vaccine for children without delay.
- Monitor Symptoms: Individuals showing fever and respiratory symptoms—particularly children, the elderly, and those with underlying illnesses—should seek prompt medical evaluation.
- Recognize Warning Signs: Parents should rush a child to urgent care if they exhibit worsening conditions such as:
- Shortness of breath or wheezing.
- Cyanosis (bluish discoloration).
- Chest pain or confusion.
- Persistent high fever or convulsions.
- Masking and Isolation: High-risk individuals should wear surgical masks in crowded settings. Anyone with respiratory symptoms should seek medical advice and consider refraining from attending school or work to prevent community spread.
The recent severe pediatric case serves as a stark reminder of influenza morbidity and the crucial role that seasonal vaccination plays in preventing severe outcomes and complications like encephalopathy. Public health officials continue to stress that vaccination is the most effective defense against the circulating strains.