 is a common respiratory virus that can circulate in Hong Kong throughout the year.){kind=link}
What Is RSV?
Respiratory syncytial virus (RSV) is a common respiratory virus that can circulate in Hong Kong throughout the year. It can infect the airways, lungs and middle ear. The virus spreads through droplets, contact with an infected person’s nasal or throat secretions, and contaminated hands, utensils or surfaces. The incubation period is usually four to six days. Common symptoms include a runny nose, cough, fever, reduced appetite and tiredness. Most adults experience mild illness, but RSV can affect different age groups in very different ways.
Risks for Different Age Groups
Infants and children under five account for a large proportion of RSV-related hospital admissions in Hong Kong. Infants aged six months or younger require particular attention. Because young children have narrower airways, an RSV infection can develop into bronchiolitis or pneumonia more easily. An infant may have a persistent cough, reduced feeding, fast breathing or unusual tiredness without a high fever. Parents should therefore monitor breathing and feeding, not temperature alone.
School-age children and young adults usually experience symptoms similar to those of a common cold, with recovery taking about one to two weeks. However, people with asthma, congenital heart disease, chronic lung disease or a weakened immune system may develop more serious lower respiratory tract infections. Even when a child has only mild symptoms, the child may still bring the virus home and pass it to younger siblings, pregnant women or older family members.
Pregnant women generally do not develop severe RSV disease. However, they can pass antibodies to the fetus through the placenta. This maternal immunity may help protect the baby during the first few months after birth, when the risk of severe RSV disease can be higher. Pregnant women should discuss vaccination with an obstetrician or family doctor, who can consider their health history and the latest safety information.
**Older adults—particularly those aged 75 and above, residents of residential care homes, and people with heart disease, chronic obstructive pulmonary disease, asthma, diabetes or weakened immunity—**are more likely to develop pneumonia, worsening of existing illnesses, hospitalisation or, in severe cases, death. In Hong Kong, RSV-related deaths have mainly occurred among older adults, and the risk increases with age.
Preventing RSV: Everyday Habits Still Matter
Vaccination is not the only way to prevent RSV. Wash your hands frequently with soap and water for at least 20 seconds, especially before touching your mouth, nose or eyes and after coughing or sneezing. Cover your mouth and nose with a tissue or your elbow when coughing or sneezing. Clean frequently touched toys, door handles, furniture and other household surfaces. Keep indoor areas well ventilated, and avoid allowing family members with respiratory symptoms to come into close contact with infants, older adults or people with weakened immunity.
Anyone with a fever or respiratory symptoms should wear a surgical mask, avoid work or school, limit visits to crowded places and seek medical advice early. An infant who has difficulty breathing, bluish lips, marked drowsiness, persistent refusal to feed or significantly fewer wet nappies should receive urgent medical attention.
Treatment: Supportive Care Is Usually the Main Approach
Most RSV infections do not require a specific routine antiviral treatment. Care usually focuses on rest, adequate fluids and relief of fever or discomfort according to advice from a doctor or pharmacist. Infants and young children should not be given cough medicines or adult medicines without professional advice.
Severe cases may require oxygen therapy, intravenous fluids or tube feeding. Doctors may consider antiviral treatment for people with severely weakened immunity in selected situations. Antibiotics do not treat the virus itself. They may be prescribed only when a bacterial complication, such as bacterial pneumonia or an ear infection, is also present.
RSV Vaccines and Protection for Expectant Mothers and Infants
RSV vaccines are registered in Hong Kong. However, Hong Kong’s current position is not to recommend universal RSV vaccination for all older adults or all pregnant women. Older adults, especially those aged 75 or above or living in residential care homes, may consult their family doctor about the expected benefits, possible risks and personal need for vaccination before making an individual decision. Pregnant women may discuss the potential benefits and risks of maternal RSV vaccination with their obstetrician. This is also not currently a universal vaccination programme in Hong Kong.
Internationally, two main approaches are used to protect infants. A pregnant woman may receive a single dose of an RSVpreF maternal vaccine during the third trimester, allowing antibodies to cross the placenta and provide protection to the baby. Alternatively, an infant may receive a long-acting monoclonal antibody, such as nirsevimab, after birth to help prevent severe RSV disease. The appropriate approach depends on local transmission patterns, product availability and medical guidance. Not every infant needs both options.
The most important point is that RSV vaccination does not replace hand hygiene, good ventilation and measures to prevent close-contact transmission. If a household includes a newborn baby, an older adult or someone with a chronic illness, tell the doctor about the person’s medical history, vaccination schedule and individual risk factors. A healthcare professional can then recommend the most suitable protection plan. This article is intended for general health education. Vaccination and treatment decisions should be based on advice from a qualified healthcare professional.
Important reminder: Seek urgent medical help if an infant develops breathing difficulty, bluish lips, refuses feeds or becomes unusually drowsy. Older adults should seek immediate medical attention for shortness of breath, chest pain, confusion or persistent high fever.