Respiratory syncytial virus

  • Respiratory syncytial virus (RSV) is a very common virus that usually causes mild cold-like symptoms.

    What is RSV?

    Respiratory syncytial virus (RSV) is a very common virus that usually causes mild cold-like symptoms.

    Most of us with healthy immune systems will not be harmed, but babies who are born prematurely, or young children who have lung disease, are at high risk of becoming unwell, often seriously, from RSV.

    RSV causes inflammation and blockage of the tiniest airways in the lungs (acute bronchiolitis). It is the most common reason for a child to be admitted to hospital with a lung infection in Europe.

    Who is most at risk?

    Infants most at risk from RSV are:

    • premature babies in the first few months of their life;
    • babies born very early who need additional oxygen for more than one month after birth;
    • babies with congenital heart disease;
    • babies with immune problems; and
    • babies with cystic fibrosis.

    By the age of two, virtually all children in the UK will have developed antibodies to RSV. This means they have come into contact with the virus and built up some resistance to it. Older children and adults, especially the elderly, can also contract RSV.

    What are the symptoms?

    Cases of RSV infections are highest between November and February. Early symptoms include:

    • a cold
    • runny nose
    • mild fever
    • sore throat
    • mild cough
    • blocked nose
    • ear infection

    After three to five days, symptoms may get worse as the virus spreads to the lungs and causes bronchiolitis. The symptoms of bronchiolitis include:

    • breathlessness
    • rapid breathing
    • wheezing
    • a strong cough.

    RSV can also cause acute viral croup (obstruction of the voice box), bronchitis or pneumonia. 

    How do you get RSV?

    RSV infection is thought to be spread mainly by physical contact, especially by hand. The virus can survive for several hours on toys, work surfaces and on used tissues. It can also be passed through sneezing and coughing like the common cold.

    What treatments are available?

    Paracetamol - available specially for babies - is helpful in reducing raised temperatures and making infants feel more comfortable.

    Short-term immunisation can be given to high risk babies - through a series of injections - in the first few months of life. However, this treatment is very expensive and not available under the NHS in all places in the UK. Ask your GP for further information.


    There are simple actions you can take to help your child avoid infection:

    • Wash your hands frequently, especially before handling your baby. You should make sure family members and carers do this too.
    • Use a tissue when you cough or sneeze and throw the tissue away immediately.
    • Try to keep your baby away from other people with coughs and colds - particularly during winter. If your child is at high risk try to avoid crowded places.
    • Wash toys used by children who have cold symptoms. Viruses can live on the surfaces of tables and toys for several hours.
    • Discourage other people from kissing your baby.
    • Do not expose your child to cigarette smoke - either in your home, or outside.
    • If your baby has a cold that doesn't improve quickly or if you have any questions regarding your baby's condition, ask your doctor for advice.

    Long-term effects

    Some babies with RSV continue to have recurrent chesty symptoms throughout childhood. It is estimated that, of the 20,000 babies admitted to hospital with the disease, 30 per cent will still be having wheezing episodes 10 years later.

    You may also find the information on the 'Bronchiolitis and your baby' page on our website useful.

    Order our RSV leaflet

    Reference: FL20