RSV in Babies: The Virus Every Parent Needs to Hear About (And What to Watch Out For)
- Isabelle Lai
- 12 hours ago
- 6 min read
When you have a baby, everyone talks about sleep. Feeding. Milestones. But one thing many parents don’t hear much about? Respiratory syncytial virus or RSV.
Yet studies show around 2 in 3 babies worldwide will catch it before their first birthday.1
It’s called Respiratory syncytial virus or RSV - and more parents need to have this conversation about it.
According to the World Health Organisation, RSV is one of the most common causes of acute lower respiratory infections in children globally.
We spoke with Dr Su Siew Choo, a Consultant Paediatrician who specialises in Paediatric Respiratory Medicine at Pantai Hospital Kuala Lumpur, to find out all about it.
What exactly is RSV?
RSV stands for Respiratory Syncytial Virus, and it’s a common virus that affects babies, kids, and adults.
However, it can be especially severe for babies, the elderly, and those with compromised immune systems.
Dr Su notes that RSV affects the airways and lungs in babies and many of them get infected even before their first birthday.
The tricky thing about RSV is that it can look exactly like a normal cold. Runny nose. Cough. Sneezing. Maybe a mild fever. This is why many parents don’t realise it’s RSV at first.
But WHY are babies so vulnerable to the virus?
Dr Su says it’s because the immune systems of babies under one are still developing.
“So it takes longer for their bodies to mount a strong defence against viruses. This is why RSV infections can progress more rapidly and lead to more severe illness in infants,” she says.
Dr Su emphasises that early prevention and added protection is especially important during the first year of life.
She shares an unexpected fact: Parents may think that babies who are high risk like pre-term babies may get hospitalised due to RSV but in actual fact, most RSV hospitalisations actually happen in babies who were born healthy and full-term.
“Every baby is at risk of RSV, which circulates all year-round in Malaysia. Parents are therefore encouraged to remain vigilant and to seek prompt medical attention if any symptoms appear,” she says.
What do the statistics say for Malaysian cases?
Let’s take a quick look at RSV cases in Malaysia (references listed at the end of this article):
RSV is the most commonly identified respiratory virus in children aged 6 months and below. Additionally, it accounts for 81% of viral respiratory tract infections.2
It infects 2 out of 3 children before 12 months of age.3
RSV causes 7 out of 10 viral lung infections in children under 5 years old.4
More than 80% of RSV hospitalisations occur in healthy children.5
About 1 in 7 children hospitalised due to RSV need intensive care.v
RSV is present all year-round. In Peninsular Malaysia, more pronounced infection peaks are observed either during the third quarter or the end of the year. As for East Malaysia, an earlier infection peak was observed from March to August. v
What actually happens in a serious RSV case?
Most babies recover well. But for some, RSV can sometimes move into the lower airways and lead to serious respiratory infections like bronchiolitis and pneumonia.
In fact, Dr Su says that RSV is a leading cause of bronchiolitis and pneumonia in babies under one year old.
When this happens, babies may need hospital care and closer monitoring - something no parent wants to go through.
“Hospitalisation or ICU attention may be required when the child is experiencing significant breathing difficulties, dehydration, or low oxygen levels,” says Dr Su.
She adds that there is currently no specific treatment for RSV, and care mainly focuses on relieving symptoms and supporting recovery.
“Is it just a cold?” Signs to watch out for
This is probably the hardest part. Because at first, RSV can present as an “ordinary” cold.
You may notice:
✔ Runny nose
✔ Cough
✔ Sneezing
✔ Mild fever
✔ Baby feeding a little less
Dr Su’s advice is to watch closely for symptoms involving the lower airways:
These include:
Wheezing
Rapid or laboured breathing
Chest retractions (when the skin pulls in around the ribs or neck with each breath)
Bluish lips or skin
Unusual sleepiness
Spasms in the airways (bronchospasms)
Dr Su’s tip: “If your child is exhibiting any of the symptoms above, do NOT wait. Bring them to the Emergency Room immediately - they will need to be seen by a doctor as soon as possible.”
Trust your instincts too. If something feels off despite a lack of urgent symptoms, bring them to your doctor.
How do babies catch RSV?
RSV is spread through droplets when someone coughs, sneezes, kisses baby, or has close contact with your baby.
It can happen through:
Older siblings coming home from school
Visitors with “just a little cold”
Daycare
Confinement centres
Shared toys and surfaces
The virus can also survive on hard surfaces such as toys, cribs and utensils for several hours.
“Babies can become infected when they touch these contaminated surfaces and then touch their eyes, nose, or mouth,” says Dr Su. (Editorial note: Suddenly all the pain of toy wiping and sanitising feels extra worth it 😅)
Small things parents can do every day
While most RSV infections are mild, serious illness can develop quickly.
As they say, prevention is the best cure. Here are some everyday habits we can adopt to lower exposure risk to RSV:
Wash hands often and thoroughly with warm, soapy water
Wear a mask if you’re unwell
Clean toys and shared surfaces regularly
Limiting close contact with people who are unwell
Be extra mindful with newborns
Can RSV be treated or prevented?
Although there is no direct treatment for RSV as yet, Dr Su says that there are currently two preventive options that parents can learn more about such as maternal vaccination during pregnancy and infant immunisation when the baby is born.
Vaccination during pregnancy allows protective antibodies to be passed from mother to baby before birth.
The second option is infant immunisation using monoclonal antibodies to provide babies with immediate protection against RSV.
“This provides babies with direct, immediate ready-made protection from the start of life, rather than relying on their own immune system to develop antibodies over time,” she says.
In fact, even if a mother has taken maternal vaccination against RSV, a newborn baby can receive immunisation with monoclonal antibodies after six months to provide continued protection against the year-long RSV circulation in Malaysia.
This is particularly important for very young infants who are at risk of developing severe RSV and you never know when your baby may get infected.
Dr Su says that the important thing is just for parents to be aware about RSV so they can make informed choices and stay vigilant to protect their baby' s health.
“Awareness matters because many parents only hear about RSV after they’ve gone through it,” she says.
One last thing parents should know
RSV is common. Not every case becomes severe.
But awareness matters because many parents only hear about RSV after they’ve lived through it.
And sometimes, simply knowing what to look for - and knowing prevention options exist, can help parents feel more informed and prepared during those early months.
Because if there’s one thing parenthood teaches us, it’s that information matters.
What to watch for
When to seek help
Available prevention options
Protect your baby directly against RSV. Speak to your paediatrician or other healthcare providers about infant immunisation with long-acting monoclonal antibodies. Visit TogetherAgainstRSV.my to learn more.
This article was created in collaboration with Sanofi as part of IBU Family's educational content series, helping parents navigate important health topics with confidence and awareness.
MAT-MY-2600016-1.0-01/2026
References:
1. Walsh E. Clin Chest Med 2017; 38(1): 29–36.
2. Khor CS, Sam IC, Hooi PS, Quek KF, Chan YF. Epidemiology and seasonality of respiratory viral infections in hospitalized children in Kuala Lumpur, Malaysia: a retrospective study of 27 years. BMC Pediatr. 2012;12:32. Published 2012 Mar 20. doi:10.1186/1471-2431-12-32
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