Respiratory syncytial virus (RSV)

RSV (respiratory syncytial virus) is a common winter virus, which almost all children have had by the time they are two years old. It is common for older children and adults to have the virus again.

For most people, RSV causes a mild illness, such as a cough or cold. However, babies under one year of age and older adults are at risk of becoming very unwell. Sometimes, people who get ill from RSV infection need to go to hospital. RSV can be more dangerous for some people, especially those with certain health conditions. It may even cause death.

• RSV can occur all year round but is more common during the autumn and winter.  
• More than 1,000 babies in Wales end up in hospital because of the virus. The number of people going to hospital because of RSV has increased in the last 20 years.   
• If you have had an RSV infection in the past, it does not mean you cannot get RSV again.  

What are the symptoms of RSV in babies? 

The most common symptoms of RSV include:  

• a runny or blocked nose  
• a fever  
• rapid or noisy breathing   
• a wet-sounding, chesty cough    
• tiredness  
• being unsettled or difficult to comfort, and  
• difficulty feeding.   

Babies are also at risk of getting lung infections such as:   

• bronchiolitis, and   
• pneumonia.   

RSV may also cause other conditions in young children, for example:  

• a barking cough (croup), and 
• painful infection inside the ear (otitis media).  

RSV is the most common cause of bronchiolitis in young babies. Bronchiolitis is a lung infection which makes it difficult to breathe and feed. It affects babies and children under two and can usually be treated at home. However, in some cases it can be severe and your child may need intensive care. It can sometimes lead to death.   

Illness due to RSV has a big impact on the NHS during winter months. In the UK, around 33,500 children under the age of five end up in hospital because of the virus. More than 1,000 babies in Wales end up in hospital because of the virus. Each year, up to 1000 people aged over 75 need hospital care due to RSV, and some of these people may die. The number of people going to hospital because of RSV has increased in the last 20 years.

How does RSV spread? 

RSV is spread through close contact with infected people. When infected people cough or sneeze, they release tiny droplets containing the virus into the air. RSV can also be spread by people touching surfaces or objects that have the virus on them. Most people will have had the virus before as a child. However, having a previous RSV infection may not mean you continue to be protected, so you could get RSV again. 

To help stop RSV and other viruses spreading, remember to:  

High-risk groups

RSV can make newborn babies and infants very unwell. Babies can develop severe lung problems, such as bronchiolitis (swelling of the small airways in the lungs) and pneumonia (swelling of the air sacs in the lungs). Babies with bronchiolitis or pneumonia may need to go to hospital to help them get better. 

RSV is the most common cause of bronchiolitis in infants. Bronchiolitis can make it hard for young children to breathe, especially in:  

• babies who have severe problems with their immune systems.
• babies born early (at 35 weeks or earlier)  
• babies with certain heart or lung problems, or  
• babies who have severe problems with their immune systems.

In older adults, RSV can cause severe breathing problems, particularly in those who are frail or have other health conditions. For a small number of people who are at risk of more severe respiratory disease, RSV infection might cause pneumonia (infection of the lungs) or even death.

Learn more

If you would like to learn more about the vaccine, or the diseases they protect against a number of information resources are available to help below.

You can also call NHS 111 or your GP practice for advice if you have any questions.