Respiratory syncytial virus (RSV)

This advice applies across the UK.

RSV (respiratory syncytial virus) is one of the most common viral causes of coughs and colds in winter.

We’ve put together the information on this page to help you protect your child from the virus, better understand the symptoms, and know what to do if your baby or child becomes very unwell with breathing difficulties. 

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In this article

What is RSV?

RSV (respiratory syncytial virus) is one of the most common viruses that cause coughs and colds. It circulates widely in the UK in the autumn and winter months, peaking in December. Almost all children are infected with the virus by the time they’re two years old.

The virus works by entering the windpipe and making its way down to the smallest airways in the lungs (bronchioles). The infection causes inflammation or swelling in the small airways and excess mucous. Swelling can narrow and block the child’s airways, so it is harder for them to breathe.

RSV & bronchiolitis

RSV may cause a cough or cold in children and adults, but in young children it is the main cause of bronchiolitis. In fact, it’s the most common cause of bronchiolitis in children under two. This is because babies and young children have small, underdeveloped airways.

Most cases of bronchiolitis are mild, and children recover without treatment within two to three weeks. Some children are more vulnerable to the virus and breathing problems, so it is important to look out for more serious problems.

Who RSV affects most

Parents need to be especially vigilant if their child or baby:

• Is under three months old. 
• Has chronic lung disease, including bronchopulmonary dysplasia.
• Has significant congenital heart problems.
• Was born prematurely (under 32 weeks).
• Has a neuromuscular disorder.
• Is immunodeficient.

How RSV spreads

The virus spreads through coughing and sneezing.  Children can breathe in tiny droplets of liquid in directly from the air or pick it up from an infected surface, like toys or a table. 

Your child can become infected after touching a toy that has the virus on it and then touching their eyes, mouth, or nose. The virus can survive on a surface for up to 24 hours. A child can remain infected with RSV for up to three weeks even after the symptoms have vanished. 

Signs and symptoms of RSV

Early symptoms usually appear a few days after becoming infected and are like a common cold, such as a blocked or runny nose, cough or slightly high temperature.

Symptoms can appear worrying and usually get worse between the third and fifth day before gradually improving.

Symptoms may include: 

• Dry, rasping and persistent dry cough.
• Difficulty feeding.
• Rapid or noisy breathing (wheeze).
• Brief pauses in breathing. 
• Fewer wet nappies and smaller appetite/taking fewer feeds.
• Vomiting after feeding.
• Irritability.

See your GP or call NHS 111 if:

• You’re worried about your child.
• Your child has taken less than half their usual amount during the last 2 or 3 feeds, or they have had a dry nappy for 12 hours or more.
• Your child has a persistent high temperature of 38C or above.
• Your child seems very tired or irritable.

Call an ambulance (999) if: 

• Your child has severe breathing difficulties or is exhausted from trying to breathe. 
• You can see the muscles under their ribs sucking in with each breath. 
• Your child is grunting (making a sound when breathing out) with the effort of trying to breathe.
• There are long pauses in your child’s breathing.
• Your child’s lips or tongue are blue.

For more information on breathing difficulties in children and when to call an ambulance, visit the British Lung Foundation website. 

Treatment for RSV

Most children get better from RSV within two-three weeks, while some will still have symptoms after four weeks.  A small number of children will have severe infection and need hospital treatment.  

Easing symptoms at home

These care tips can help ease your baby or child’s symptoms. Do not hesitate to contact your GP or out-of-hours service if their condition worsens. 

• Check on your child regularly, including during the night.
• Avoid sending your child to nursery or childcare until the symptoms have gone – RSV is very infectious.
• Avoid smoking in the house and anywhere near your child.
• Keep your child upright. It may make it easier for them to breathe and feed.
• Try giving babies smaller breast or bottle feeds more often.
• Supplement breast or bottle feeds with water or diluted fruit juice to prevent them becoming dehydrated.
• If your child has a high temperature (fever) use paracetamol or ibuprofen, depending on their age.
• Use saline (salt water) nose drops, available from pharmacies without prescription, before a feed to relieve a blocked nose.

Medicine

There’s no medicine that can kill the virus that causes bronchiolitis. Antibiotics and corticosteroids are not recommended for treating bronchiolitis. 

Babies and children can have paracetamol for pain or fever if they’re over two months old. You can give ibuprofen to babies aged three months or over who weigh at least 5kg (11lbs).

Always follow the manufacturer’s instructions. Do not give aspirin to children under the age of 16. Do not try to reduce your child’s high temperature by sponging them with cold water or underdressing them. 

If your child needs to go to hospital

Some children with bronchiolitis need to go to hospital. Babies and children born prematurely (before 37 weeks) are more likely to need to go to hospital.

Doctors will refer your baby or child to hospital if they are not getting enough oxygen into their blood because they’re having difficulty breathing, or if they are not eating or drinking enough.  

If you are worried, do not hesitate to contact your GP or call NHS 111. Keep these contact numbers handy.

Once in hospital, practitioners will closely monitor your child and give them various treatments, depending on their condition. 

Most children need to stay in hospital for a few days. Your child will be able to leave hospital and return home when their condition has stabilised. This will be when they have enough oxygen in their blood without the need medical assistance, and they’re able to take and keep down most of their normal feeds. Nurses will measure your child’s oxygen levels with your child’s using blood pulse oximeter, a small clip or peg that’s attached to your baby’s finger or toe.  

The hospital may also: 

• Give your child more oxygen through thin tubes in their nose or a mask that goes over their face. 
• Take a sample of your child’s mucus to test whether RSV is causing the bronchiolitis. If your child has RSV, the hospital will keep your child away from other children in the hospital to stop it spreading. 
• Give your child fluids or milk through a feeding tube (nasogastric tube), a thin plastic tube that goes into your child’s mouth or nose and down into their stomach. 
• If your child is at high risk of respiratory failure or cannot use nasogastric fluids, the hospital may give them fluids directly into a vein (intravenously). 
• Nasal suction is not routinely used in children with bronchiolitis. But it may be recommended if your child’s nose is blocked and they’re having trouble breathing. A small plastic tube will be inserted into your child’s nostrils to suck out the mucus. 

Reducing the risk of catching RSV

RSV spreads easily, so it’s impossible to completely prevent it. But there are ways to reduce the risk:

• Wash your and your child’s hand often, and ask people in contact with your child to wash their hands first.
• Use disposable tissues rather than handkerchiefs, and throw them away as soon as you’ve used them.
• Cover your child’s nose and mouth when they cough or sneeze.
• Wash and dry eating utensils after use.
• Wash or wipe toys and surfaces regularly.
• Keep infected children at home until their symptoms improve.
• Keep newborn babies away from people with colds and flu.
• Never smoke around your child.

Antibody injections

Children at high risk of developing severe bronchiolitis may be able to have monthly antibody injections (Palivizumab) during the winter (November to March). Children considered to be at high risk include: 

• Children born very prematurely.
• Children born with a heart or lung condition.
• Children with an immune deficiency (weakened immune system).

The injections may help limit the severity of bronchiolitis if your child becomes infected. But they can be expensive and are not always available on the NHS. Speak to your GP if you think your child has an increased risk of developing severe bronchiolitis.

Vaccination

For the first time, from 1 September 2024 the NHS will vaccinate pregnant women from 28 weeks onwards and adults 75 and over against RSV.

Pregnant women will be offered the vaccine in their antenatal appointment. Older people will be invited to get the vaccine by their GP surgery.

Find out more about RSV vaccination (⧉ NHS)

Podcasts and video

RSV podcast episodes

Watch our winter illnesses Q&A session recording

Great Ormond Street Hospital respiratory paediatrician Dr Martin Samuels answers parent questions about flu, RSV, Strep A and more.

Video: Protecting your child from RSV and other winter viruses