Flu is an acute infectious disease caused by Influenza virus, primarily types A and B. It spreads through the respiratory tract and can develop into an epidemic. Characteristic symptoms include sudden high fever, muscle aches, extreme fatigue, coughing, and a sore throat.

Master of Science, Doctor Tran Van Ha, from the Pediatrics Department at Tam Anh General Hospital Hanoi, stated that seasonal changes significantly increase the risk of illness for children. Understanding these causes will enable parents to implement proactive preventive measures.

Erratic weather changes

As autumn transitions to winter, daily temperatures fluctuate considerably. Chilly mornings, hot and humid afternoons, and cold nights create ideal conditions for bacteria and viruses to multiply and thrive. Flu viruses survive longer in low temperatures and high humidity. Children's underdeveloped thermoregulation systems make them susceptible to viral attacks if they are not dressed warmly enough or if they sweat and do not change clothes promptly.

Doctor examines a child with high fever during seasonal changes. *Illustration: Tam Anh General Hospital*

Immature immune system

During weather changes, children's ability to adapt and resist pathogens is limited due to their weaker immune systems compared to adults. Children under 5 years old are also prone to respiratory illnesses such as pneumonia, bronchitis, and tonsillitis. Children with allergic conditions are susceptible to recurrent allergic rhinitis and bronchial asthma during seasonal transitions.

Inadequate personal hygiene

Seasonal flu often spreads rapidly in communal environments. Young children frequently lack proper personal hygiene skills, such as regular handwashing and covering their mouths when coughing or sneezing, which increases the risk of viruses easily entering their bodies.

Incomplete vaccination

Unvaccinated children are more likely to contract the disease when exposed to sources of infection or viruses circulating in the environment. Doctor Ha explained that complete vaccination helps establish herd immunity, protecting even those unable to receive vaccines (such as infants under 6 months old). Antibodies produced by vaccines decrease over time, and flu viruses constantly mutate annually, therefore requiring annual booster shots to maintain protection.

During periods of increased flu prevalence, Doctor Ha advises parents on how to prevent illness in children: keep them warm, enhance nutrition, ensure body and living environment hygiene, and follow the scheduled vaccination plan. If a child experiences high fever, persistent coughing, wheezing, or prolonged diarrhea, they should be taken to the hospital immediately, avoiding self-medication.

Thanh Ba