Influenza, commonly known as the flu, spreads easily through respiratory droplets when individuals inhale particles from coughs, sneezes, or conversations. It can also transmit via hands that have touched contaminated surfaces, then come into contact with the eyes, nose, or mouth. Since the beginning of the year, Vietnam has seen numerous flu cases silently escalate into severe conditions, leading to pneumonia, respiratory failure, and requiring mechanical ventilation. This occurs even when patients initially exhibit only mild symptoms like fatigue, headache, fever, and a cough for a few days. In late April, the Central Hospital for Tropical Diseases reported a rise in severe Flu B cases among elderly patients with underlying health issues. Among them, three elderly men, aged 77, 65, and 60, developed complicated pneumonia and respiratory failure due to fungal and bacterial superinfections, necessitating mechanical ventilation.

A 60-year-old patient from Hai Duong, with underlying conditions of diabetes and hepatitis B, developed severe pneumonia from flu complications and required mechanical ventilation at the Central Hospital for Tropical Diseases. Photo: BVCC

According to Doctor of First-Degree Specialization Tong Thi Ngoc Cam, Deputy Medical Director for the Northern Region at the VNVC Vaccination System, the most effective way to prevent flu infection and severe complications is through vaccination and annual booster shots, as recommended by the World Health Organization (WHO). This is because the flu virus constantly mutates, and antibodies from vaccination decline after 6-12 months. Booster shots are essential to enhance protective efficacy.

To ensure effective vaccination, Doctor Cam advises people to adhere to recommendations and learn about disease prevention, avoiding unnecessary misconceptions.

The doctor cited the case of a 69-year-old female patient from Duc Nhuan ward, TP HCM, who stopped receiving flu vaccines after retirement, believing it was no longer necessary. She reasoned that staying home more often, exercising regularly, maintaining a healthy diet, and wearing a jacket and mask outdoors were sufficient for flu prevention, so she skipped booster shots. "I thought I had received many flu shots already; getting more would overload my immune system," she shared.

During the first one or two years, she felt her decision was correct, experiencing only normal health, with perhaps a mild cough or sore throat that responded to salt water gargles and ginger tea. In subsequent years, however, she experienced prolonged coughing or coughing with thick phlegm whenever the weather changed, she drank cold water, or after traveling. The situation peaked in 2023-2024 when she contracted the flu frequently, with five consecutive infections in the last four months of 2024 alone.

In addition to medical examinations and prescribed medications, she also used traditional remedies such as steamed herbal water, ginger tea, and kumquat water with rock sugar and honey. However, as soon as one bout of illness subsided, she would quickly get reinfected. Notably, she was hospitalized for nearly a month to treat pneumonia, a severe complication caused by the flu. The patient stated that she resumed flu vaccination in 2/2025. Besides the flu shot, she also received other vaccines, including pneumococcal, dengue, meningococcal, and hepatitis B.

An elderly patient is brought by his grandson to VNVC Hoang Van Thu for a flu booster shot after two years of skipping it, believing that two flu shots were sufficient. Photo: Dieu Thuan

Many other misconceptions about flu vaccines persist, such as beliefs that the vaccine is ineffective, that one can still get sick after vaccination, or that flu is a common illness not requiring vaccination.

According to Doctor Cam, these are incorrect beliefs that increase the risk of flu infection and severe complications caused by the flu virus. This is particularly true for the elderly, who often have weakened health, aging immune systems, and multiple underlying conditions, placing them in a high-risk group for flu. The illness often presents with fever, fatigue, body aches, and a cough, similar to a common cold. This leads many elderly individuals to self-treat with over-the-counter medications, herbal steaming, or acupuncture. However, the disease can silently worsen, causing shortness of breath, thick phlegm, low blood pressure, and rapid breathing.

If left untreated, the flu can lead to severe complications, necessitating mechanical ventilation, intensive care unit (ICU) admission, and even extracorporeal membrane oxygenation (ECMO), incurring significant costs. The flu virus can also lead to superinfections with other bacteria and viruses such as respiratory syncytial virus (RSV), pneumococcus, Staphylococcus aureus, and fungi, further increasing the risk of severe pneumonia, respiratory failure, multi-organ failure, and death.

Currently, Vietnam utilizes four types of flu vaccines from France, the Netherlands, South Korea, and Vietnam. Beyond preventing illness, these vaccines reduce the risk of hospitalization by 90% and the risk of mortality by 70-80% in high-risk groups. Furthermore, a recently published study indicates that adequate flu vaccination may also help reduce the incidence of Alzheimer's disease.

All four flu vaccines offer protection against common Flu A and Flu B strains and are suitable for children from 6 months old to adults. Elderly individuals should receive one dose and an annual booster to enhance their immunity. The elderly are also vulnerable to other conditions, including pneumococcal pneumonia, RSV pneumonia, whooping cough, and shingles. Therefore, comprehensive vaccination is crucial for preventing these diseases and their associated complications.

Dieu Thuan