Bronchiolitis and RSV in Babies: What UK Parents Should Know This Autumn

Quick answer: Bronchiolitis is a common chest infection in babies and children under 2, usually caused by RSV. It starts like a cold, then brings a cough, faster breathing, wheezing or crackly breathing, and feeding less than usual. Symptoms are usually worst on days 3 to 5. Most babies recover at home, but call 999 if breathing is laboured, paused or your baby is floppy.

What parents need to know

RSV infections can happen all year round but cases peak every winter, and bronchiolitis is a major cause of hospital admission for babies under 6 months. Knowing the difference between an ordinary cold and the signs that need urgent help takes a lot of the fear out of the season.

What is bronchiolitis, and how is it different from a cold?

Bronchiolitis is a common chest infection affecting babies and children under 2, most often in the first year of life, with cases peaking between 3 and 6 months of age. It is usually mild and can be looked after at home, though it can be serious in some children.

It is not the same as bronchitis, which causes a cough with lots of mucus and affects people of all ages. Bronchiolitis is caused by a viral infection, usually respiratory syncytial virus (RSV) — a virus so common that almost all children catch it at least once before they are 2.

The pattern is fairly typical: a cold-like start with a runny or blocked nose lasting 1 to 3 days, followed by a persistent cough alongside fast breathing or the chest being drawn in, and wheeze or crackles in the chest.

What are the symptoms of bronchiolitis in a baby?

The early symptoms look like an ordinary cold: sneezing, a runny or blocked nose and a slightly high temperature. This cold-like phase usually lasts 1 to 3 days before other symptoms appear.

A fever happens in around 30% of cases and is usually below 39°C. Poor feeding typically shows up after 3 to 5 days of illness. In very young infants, particularly those under 6 weeks, bronchiolitis can occasionally present as pauses in breathing (apnoea) without any other obvious signs.

Symptoms are usually worst between days 3 and 5. The cough takes longer to settle — it resolves in around 90% of infants within 3 weeks, so a lingering cough after the worst has passed is not unusual.

• Cough — A persistent cough that develops after the cold-like phase of 1 to 3 days.
• Faster breathing — Your baby is breathing more quickly than their usual rhythm.
• Noisy breathing — Wheezing or crackling sounds as they breathe.
• Feeding less — Finding it difficult to feed or eat, typically after 3 to 5 days of illness.
• Irritability — Becoming unsettled, difficult to comfort, or simply not themselves.

How do you care for a baby with bronchiolitis at home?

There is no specific treatment for bronchiolitis. It usually gets better on its own and you can look after your child at home, although some children do need to be treated in hospital.

It is also worth knowing what not to do. Do not smoke around your child, do not try to lower their temperature by sponging them with cool water or taking off all their clothes, and do not give aspirin to a child under 16.

1. Keep fluids going — Encourage your child to drink lots of fluids — try smaller, more frequent feeds in babies, and extra water or diluted fruit juice in older children.
2. Keep them upright when awake — Holding your baby upright as much as possible while they are awake helps them breathe more easily.
3. Check on them regularly — Including during the night, so you notice any change in their breathing or alertness.
4. Use pain relief if needed — Children's paracetamol for babies and children over 2 months, or ibuprofen for babies and children over 3 months, if they are distressed or uncomfortable. Do not give these medicines at the same time.

Which babies are at higher risk of severe bronchiolitis?

Most babies cope well, but some have a higher chance of becoming seriously ill. That includes babies under 6 months, babies born prematurely, and babies with a weakened immune system or a long-term lung or heart condition.

Clinicians also take into account chronic lung disease (including bronchopulmonary dysplasia), haemodynamically significant congenital heart disease, neuromuscular disorders, immunodeficiency, premature birth particularly under 32 weeks, and age under 3 months when deciding whether a baby needs hospital assessment.

Babies at higher risk may be offered an injection of infection-fighting antibodies each winter, which helps reduce the risk of RSV causing severe bronchiolitis. This provides additional protection on top of any antibodies passed on from a vaccinated mum.

How does the RSV vaccine in pregnancy protect a newborn?

The RSV vaccine is available free on the NHS from 28 weeks of pregnancy, and is recommended in every pregnancy. It boosts your immune system to produce more antibodies, which pass through the placenta to help protect your baby from the day they are born.

UKHSA guidance says RSV vaccination reduces the risk of severe bronchiolitis by 70% in the first 6 months of life — the window when babies are most likely to become seriously ill. After this age your baby is at much lower risk of severe RSV.

You should be offered the vaccine around the time of your 28-week antenatal appointment. Having it then, or within a few weeks, gives your baby the best protection, including if they are born early. It can still be given later, right up until you go into labour, but may be less effective; very late vaccination may still protect you and reduce the risk of passing RSV to your newborn. If you are 28 weeks or more and have not been offered it, speak to your maternity service or GP surgery.

The vaccine is also offered to adults aged 75 or over, and to adults aged 65 to 74 who have a weakened immune system or a long-term lung condition (this does not include asthma that is under control) — worth knowing if grandparents are helping with a newborn.

How can you reduce the chance of your baby catching RSV?

RSV is highly infectious and spreads easily through coughing and sneezing, so it is genuinely difficult to avoid spreading within a family. Simple habits still help.

Wash your hands and your child's hands often, wash or wipe down toys and clean surfaces regularly, avoid sharing things like cutlery and cups, and use disposable tissues and throw them away as soon as you have used them. Keep newborn babies away from anyone with a cold or the flu — especially if they were born prematurely or have serious health conditions.

Not smoking around your child matters here too: children who breathe in cigarette smoke have a higher risk of getting severe bronchiolitis.

Frequently asked questions

When is the RSV vaccine offered in pregnancy?

It is free on the NHS from 28 weeks of pregnancy and recommended in every pregnancy. You should be offered it around your 28-week antenatal appointment. It can still be given later, right up until labour, but may be less effective.

How long does a bronchiolitis cough last?

The cough settles slowly. It resolves in around 90% of infants within 3 weeks, so a lingering cough after the worst has passed is not unusual.

Which babies are most at risk of severe bronchiolitis?

Babies under 6 months, babies born prematurely, and babies with a weakened immune system or a long-term lung or heart condition have a higher chance of becoming seriously ill.

Can you give paracetamol to a baby with bronchiolitis?

Children's paracetamol can be used for babies over 2 months, or ibuprofen for babies over 3 months, if they are distressed or uncomfortable. Do not give these medicines at the same time.