Not just a common cold: Singapore studies show RSV’s severity and impact on long-term health

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Not just a common cold: Singapore studies show RSV’s severity and impact on long-term health

Singapore, 5 November 2025 – Often confused for a common cold, respiratory syncytial virus (RSV) can in fact be serious and should be studied more closely. In studies led by Singapore General Hospital (SGH), researchers collaborating under the Programme for Research in Epidemic Preparedness And REsponse (PREPARE)[1] found that the illness could be of comparable severity to other more well-known respiratory viral infections (RVIs) – such as influenza and COVID-19.

In three large-cohort studies, the researchers looked at the severity of RSV, risk of cardiac complications, and long-term complications in patients who had RSV infections severe enough to require hospitalisation, versus influenza and COVID-19 hospitalisations. Throughout all three studies, it was found that RSV was of comparable severity to influenza and COVID-19.

Dr Ian Wee, Consultant, Department of Infectious Diseases, SGH and Deputy Lead, Databases Core, PREPARE, and first author for all three papers, said, “With about five to ten per cent of those experiencing flu-like symptoms having respiratory syncytial virus, it may not be as common compared to influenza or COVID-19, and more research about the illness is needed. However, this does not make the infection any less serious than other RVIs, especially in Singapore’s tropical climate where year-round transmission of RSV occurs.”

Key findings

Disease severity

Published in The Lancet Regional Health, the first study examined close to 13,000 adult hospitalisations for RSV, COVID-19 and influenza, and compared risk of 28-day mortality and intensive-care-unit admission, which are indicators of severity. Among patients hospitalised for RSV, about one in 20 died within 28 days of hospital admission. Overall, hospitalisations due to RSV were more severe than influenza, with higher death rates and more intensive care admissions. RSV was of comparable severity to COVID-19 hospitalisation in individuals previously boosted against COVID-19; the study pre-dated the availability of RSV vaccination in Singapore.

Risk of cardiac complications

The second study, published in JAMA Network Open, compared the risk of acute cardiac complications – defined as any cardiac, cerebrovascular or thrombotic event, such as abnormal or irregular heartbeat, heart failure, stroke, deep venous thrombosis, or pulmonary embolism. Assessing almost 33,000 adult hospitalisations for RSV, COVID-19 and influenza, slightly more than one in ten RSV hospitalisations had an acute cardiovascular event. These odds were significantly higher than patients hospitalised for COVID-19, as well as for patients with vaccine-breakthrough[2] influenza hospitalisations. 

Long-term complications

The third study looked at long-term complications following RSV infection in adults and children. Published in Clinical Microbiology and Infection, it studied about 83,000 adults hospitalised due to RVI. In adults hospitalised for RSV, increased risk of long-term cardiovascular and neurological complications was observed up to 300 days post-hospitalisation. This study also assessed paediatric RVI hospitalisations among 24,340 patients aged 0 to 17 and found that there was higher risk of post-acute respiratory complications such as wheeze/bronchitis following RSV hospitalisation, versus COVID-19/influenza. 

Understanding RVIs and RSV

RVIs are infections caused by viruses that affect the respiratory system, from the nose and throat to the airways and lungs. Beyond RSV, influenza, and COVID-19, other viruses can also cause respiratory infections. Common symptoms of RVIs include cough, sore throat and nasal congestion; while mild and self-resolving in most instances, progression to more severe illness (e.g. pneumonia or respiratory failure) can occur, particularly amongst at-risk groups. 

RSV is a respiratory virus that causes characteristic flu-like symptoms, including runny nose and sore throat. Like other respiratory viruses, it spreads through close contact, exposure to respiratory droplets from coughing or sneezing, or contaminated objects and surfaces. Most individuals experience only mild symptoms; however, young children, older adults, those who are immunocompromised or have existing respiratory or cardiac conditions are at higher risk of severe RSV.

Dr Wee added, “One common point across the three studies was that young children and elderly patients face the greatest risk of short-term and long-term complications following respiratory viral infections, especially those with pre-existing medical conditions. RSV can have a significant impact on one’s health, and at-risk individuals should remain vigilant and discuss RSV protection with their healthcare providers. The public should also protect against all RVIs by maintaining good personal hygiene, such as practising hand hygiene, staying home if feeling unwell, and wearing a mask if needing to leave home when symptomatic.”

Full details of the three studies are available here:

Wee LE, Lim JT, Ho RWL, et al. Severity of respiratory syncytial virus versus SARS-CoV-2 Omicron and influenza infection amongst hospitalized Singaporean adults: a national cohort study. Lancet Reg Health West Pac. 2025;55:101494. Published 2025 Feb 20. doi:10.1016/j.lanwpc.2025.101494

Wee LE, Lim JT, Ho RWL, Chiew CJ, Lye DCB, Tan KB. Cardiac Events in Adults Hospitalized for Respiratory Syncytial Virus vs COVID-19 or Influenza. JAMA Netw Open. 2025;8(5):e2511764. Published 2025 May 1. doi:10.1001/jamanetworkopen.2025.11764

Wee LE, Ho RWL, Lim JT, et al. Long-term sequelae post-hospitalization for respiratory syncytial virus vs. Omicron SARS-CoV-2 or influenza in adults and children: a retrospective cohort study. Clin Microbiol Infect. Published online April 26, 2025. doi:10.1016/j.cmi.2025.04.022

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For media enquiries, please contact:

Candice Lee                                                                              

Communications Department                                              

Singapore General Hospital                                                                                                           

Email: Candice.lee.l.f@sgh.com.sg                                      

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About Singapore General Hospital (SGH)

Singapore General Hospital, established in 1821, is the largest tertiary hospital in Singapore and ranked among the world’s best. It provides the most comprehensive patient-centred care with over 50 clinical specialties on its campus. As an Academic Medical Centre, it takes pride in training healthcare professionals and conducting cutting edge research to meet evolving needs of the nation as well as the region. Driven by a strong sense of purpose, SGH is committed to give of its best to heal and bring hope, as it has for over 200 years.

For more information, please visit www.sgh.com.sg

[1] PREPARE is a national programme set up by the Ministry of Health (MOH) to support and strengthen Singapore’s key essential research capabilities, translational platforms, and expertise to develop tools, methods and products that can be tapped on to detect, respond to, and contain future infectious disease threats. PREPARE is a national programme under the Communicable Diseases Agency (CDA), and is supported by the Singapore Ministry of Health through the NMRC Office, MOH Holdings Pte Ltd under the National Epidemic Preparedness and Response R&D Programme Funding Initiative (MOH-001041/MOH-001073/MOH-001446).

[2] A vaccine-breakthrough is when a patient gets infected with the disease even though they have been vaccinated against it. This could be due to different factors, such as mutating virus strains or waning immunity.