RSV Symptoms in Babies

What is RSV?

Respiratory Syncytial Virus (RSV) is a common virus that infects the respiratory tract, and it’s particularly widespread among babies and young children. Most children will have had RSV by the age of two, and in many cases, RSV causes symptoms similar to a cold (runny nose, cough, sneezing), with children recovering without needing hospital care.

However, RSV can progress to more serious illness in infants, especially in those born premature, with underlying health issues, or very young babies. One of the things RSV can cause is bronchiolitis, an infection of the small airways in the lungs, and pneumonia.

 

What symptoms look like in babies

Because babies can’t say how they feel, RSV symptoms in infants may show up in ways that are more subtle or different from older children. According to the NHS, typical early symptoms include:

• A runny or blocked nose
• A cough
• Sneezing
• Tiredness (lethargy) or being more sleepy than usual
• A high temperature (fever)
• Babies may feed less well than usual
• Irritability

Some symptoms that suggest the illness is becoming more serious, or that RSV has led to a complication such as bronchiolitis or pneumonia:

• A worsening cough
• Faster breathing, noisy breathing (wheezing) or shortness of breath
• Long pauses between breaths
• Difficulty feeding (baby takes much less milk than usual) or losing interest in feeding
• Signs of dehydration: fewer wet nappies, dry mouth, lips etc
• Colour changes: pale skin, lips or tongue turning bluish (cyanosis)

Additionally, for very young infants (such as under 3 months), even a relatively mild fever can be more concerning. The NHS advises that for babies under 3 months, a temperature of 38°C or more should prompt medical advice.

 

What parents should do if they suspect RSV

If you suspect your baby has RSV, or is developing symptoms that may indicate RSV:

1. Monitor symptoms closely. Note whether the cough is worsening, breathing is getting more difficult, feeding is declining, or baby appears more tired or irritable.
2. Supportive home care
   • Keep them comfortable and rested
   • Maintain hydration: small frequent feeds if feeding is difficult
   • Use a cool‐mist humidifier or sit with them in a steamy bathroom to help with breathing
   • Keep the air clean (avoid smoke exposure)
   • Keep nose clear: use saline drops to help with blocked nose so they can feed or breathe better
3. When to seek medical help / call a GP or NHS 111

You should contact a health professional if:

• Baby is feeding much less than usual
• Baby has had a dry nappy for 12 hours or more (fewer wet nappies) – possible dehydration
• Temperature is elevated (as above), or baby feels hotter than usual, or is shivering
• Any signs of struggling for breath: fast breathing, wheezing, flaring nostrils, creasing around ribs, noisy breathing or pauses
• Baby becomes very sleepy or difficult to wake, or if colour changes seen (blue, grey lips etc.)

4. When it’s an emergency

If signs are severe, call 999 or take the baby to A&E. NHS red flags include:

• Breathing very fast or with difficulty, or has stopped breathing for short periods
• Lips or skin turning blue or grey
• Baby very floppy, not responsive, or showing signs of confusion

 

RSV vaccine and preventative measures

The NHS has recently enhanced measures to reduce the risk of severe RSV in newborns and babies. Some key points:

• RSV vaccine in pregnancy: Pregnant women are offered the RSV vaccine from about 28 weeks gestation. Getting it at that time helps build antibodies that cross the placenta and give the baby protection in the early months of life.
• According to NHS guidance, the vaccine is offered free if pregnant and ≥28 weeks, and also to older adults (75‐79 and people turning 80 after certain date) to protect them too.
• For babies at high risk (for example very preterm, or other vulnerability) there is a medication (monoclonal antibody), nirsevimab, being rolled out to help protect such infants who cannot rely just on the passive protection from maternal vaccination.
• Early data suggests that maternal vaccination reduces hospitalisation risk in newborns significantly.
• Other prevention steps:
  • Good hygiene: washing hands, avoiding close contact with people who are unwell
  • Avoiding smoke exposure
  • Keeping surfaces clean (door handles, toys etc.)

 

Stay vigilant and seek medical advice

RSV is common, and for most babies it’s mild. However, it can worsen, especially in younger or high-risk infants. As a parent:

• Be alert to the early symptoms (runny nose, cough, feeding less etc.)
• Know the warning signs that require medical attention
• Consider the protection offered by having the vaccine during pregnancy if you are pregnant
• If your baby is high risk, talk to your GP or paediatrician about nirsevimab or other preventative options

If ever in doubt, especially with breathing difficulty, feeding problems, or signs of dehydration, don’t hesitate to seek medical help via NHS 111, or your GP, or in an emergency ring 999.