RSV: The lesser-known risks of a common respiratory virus

Published on 29 September 2026

RSV infections receive considerably less attention than COVID-19 and influenza, but they can also cause serious illness in vulnerable populations.

At a glance

• RSV is usually associated with illness in young children, while its impact on adults is less widely recognised.
• A local study found that patients hospitalised with RSV experienced worse outcomes than those with influenza, including higher ICU admission and mortality rates.
• RSV may cause pneumonia, low oxygen levels and worsening of existing heart or lung disease.

COVID-19 and influenza are among the respiratory viruses that have dominated headlines in recent years. Yet another common virus, respiratory syncytial virus (RSV), which occurs year-round locally, has largely remained under the radar.

While RSV can cause upper and lower respiratory tract infections, these bouts of illness are often mild and self-limiting. In infants, older adults and individuals with pre-existing medical conditions, however, it can lead to severe disease.

“RSV usually causes cold-like symptoms and has traditionally been associated with illness in young children, so its impact on adults has received less attention,” explained Dr Nicholas Ngiam, Consultant, Division of Infectious Diseases, Department of Medicine, National University Hospital (NUH). “However, we recognise that RSV can also cause serious illness in older or medically vulnerable adults.”

When common symptoms become serious

Like other respiratory infections, RSV can cause symptoms such as runny nose, congestion, wheezing and coughing. While these seemingly run-of-the-mill symptoms may resolve within a week or two in healthy individuals, the illness can worsen progressively in older and medically vulnerable adults.

“RSV can cause pneumonia, breathing difficulties, wheeze and respiratory failure, and can worsen conditions such as asthma, chronic lung disease or heart failure,” Dr Ngiam said. “Those at greatest risk include older adults, particularly those who are frail, as well as people with chronic heart or lung disease, diabetes or weakened immune systems.”

Dr Ngiam commonly encounters RSV infections in clinical practice, especially among older and medically vulnerable adults admitted with respiratory infections.

“An older person with chronic lung or heart disease may initially develop what appears to be a simple cold but subsequently becomes increasingly breathless and requires oxygen and hospital admission,” Dr Ngiam explained. “The infection may also worsen their underlying medical conditions, and recovery can therefore take considerably longer than expected.”

RSV, COVID-19 and influenza: How do their risks compare?

A large Singapore study evaluating the severity of RSV in comparison to COVID-19 and influenza among adults hospitalised for these infections found that among patients hospitalised with RSV, 5.4 per cent died within 28 days and 3.8 per cent required intensive care.

After accounting for age and underlying medical conditions, patients with RSV had more than four times the odds of dying and more than twice the odds of requiring intensive care compared with those hospitalised for influenza.

While it can be difficult to identify a respiratory virus based on symptoms alone, knowing the exact virus may not always change treatment plans in cases of mild illness. “However, having a definitive diagnosis becomes more important in patients who are older, vulnerable or unwell enough to require hospital care, as influenza and COVID-19 have specific antiviral treatments,” explained Dr Ngiam.

“Identifying the virus can also help guide infection-control measures, better understand the spread of the different viruses, plan vaccination strategies and also avoid unnecessary antibiotics.”

Protecting yourself and your loved ones

RSV, like other respiratory infections, is highly contagious and can spread from person to person through respiratory droplets and contact with contaminated hands or surfaces.

“Many of the same measures used for other respiratory infections help minimise transmission of RSV,” said Dr Ngiam. “These include practising regular hand hygiene, covering coughs and sneezes, avoiding close contact with others when unwell, and wearing a mask when appropriate, particularly when around vulnerable individuals.”

 Just as RSV is less widely known than influenza and COVID-19, public awareness of the vaccine against it is also lower. “RSV vaccination is highly effective, and is also now available for selected groups,” said Dr Ngiam. “These include older adults and some people at increased risk. Individuals can discuss with their doctor whether vaccination would be appropriate for them.”

In consultation with Dr Nicholas Ngiam, Consultant, Division of Infectious Diseases, Department of Medicine, NUH.