What is RSV and who is eligible for the vaccine?

Respiratory syncytial virus (RSV) is a major respiratory virus that is most common over the winter period, typically November to February. Most cases are mild, but RSV can be serious, especially for infants and older adults.

Before the vaccine was introduced, RSV caused around 30,000 hospitalisations of children under 5 in the UK each year, and 20 to 30 infant deaths. It also caused around 9,000 hospitalisations annually in adults over 75, often triggering pneumonia or flare-ups of long-term lung conditions.

The vaccination programme is already making a difference. In 2025-26, England saw 50% fewer infants under 6 months admitted to intensive care with RSV compared with the previous season, as the maternal vaccination programme took full effect. Data also shows a sustained reduction in RSV-related hospital admissions among eligible adults aged 75 to 80.

Who is at risk?

Babies are especially vulnerable because their airways are small and their immunity is still developing. RSV can lead to bronchiolitis, a lung infection causing inflammation, and is most common in infants under one year old. Bronchiolitis differs from bronchitis, which affects people of all ages and causes a mucus-heavy cough. Severe bronchiolitis can require intensive care and can be fatal. More information on bronchiolitis is available on the NHS website.

Older adults, particularly those with lung conditions like chronic obstructive pulmonary disease (COPD) or a weakened immune system, are also at higher risk of severe RSV infection, which can require hospital admission, cause lasting loss of independence, or even be life-threatening.

How can I protect my baby from RSV?

Vaccination during pregnancy is the best way to protect newborns. It reduces the risk of severe RSV lung infection, such as bronchiolitis, by 80% in a baby's first months of life, significantly lowering the chance of hospital admission.

The vaccine works by boosting the mother's immune system to produce antibodies, which then pass through the placenta to protect the baby from birth.

It's offered from week 28 of pregnancy, usually through maternity services, though GP practices can also provide it. If you haven't been offered the vaccine around the time of your 28-week antenatal appointment, contact your maternity service. Vaccination in week 28, or shortly after, gives the best protection, including for babies born early. Later vaccination still offers some protection and can be given right up until birth if needed.

Babies born very prematurely (before 32 weeks) may need a different form of RSV immunisation, as there may not have been time for the mother to be vaccinated effectively. This also applies to babies with certain heart, breathing or immune conditions. These babies are usually immunised by hospital paediatric teams, either in the neonatal unit or at a follow-up appointment.

What are the symptoms of RSV?

RSV typically causes a cough or cold, wheezing, shortness of breath, tiredness and fever. In babies, symptoms may also include fast, noisy or difficult breathing, fussiness, irritability and reduced feeding. Most cases clear up within 2 to 3 weeks. More details are available on the NHS website.

How long is RSV contagious?

People are most contagious while symptomatic, especially early on, with most transmission occurring within 5 days of symptoms starting. However, infectious virus can sometimes be detected before symptoms appear (1 to 2 days beforehand) and can persist afterwards.

Research suggests that babies and toddlers experiencing their first RSV infection may remain infectious for 2 weeks or more, and may spread the virus more easily than those with prior immunity. People with weakened immune systems may also stay infectious for longer.

These factors make RSV difficult to avoid entirely, which is why vaccination is so important for those eligible.

Who is eligible for the RSV vaccine?

The vaccine is offered to:

pregnant women (to protect their newborn babies) adults aged 75 and over all residents in care homes for older adults adults aged 65 to 74 with a long-term lung condition (such as poorly controlled asthma, COPD or cystic fibrosis) or a weakened immune system due to disease or treatment

Visit the NHS website for full details.

Do I need more than one dose?

Pregnant women should have the vaccine during every pregnancy, to protect each new baby. For older adults, a single dose is expected to offer good protection for several years, and the programme is monitoring how long this protection lasts.

Preventing the spread of RSV

RSV spreads through coughs and sneezes. You can help reduce transmission by covering your mouth and nose when coughing or sneezing, ideally with a tissue or into the crook of your arm, and washing your hands regularly with soap and water.

If you have cold-like symptoms, try to avoid contact with young babies, particularly newborns and premature babies. It's entirely reasonable to ask people with colds to keep their distance from a new baby. Even so, RSV can still be difficult to avoid entirely.

UKHSA's role

The UK Health Security Agency leads national monitoring of RSV activity and evaluates the NHS immunisation programmes protecting infants and older adults. This includes tracking infection rates, hospitalisations and seasonal patterns, and assessing vaccine effectiveness. UKHSA also provides clinical guidance for safe vaccine delivery and supplies scientific evidence to bodies such as the Joint Committee on Vaccination and Immunisation, helping shape government policy on vaccine eligibility.

https://ukhsa.blog.gov.uk/2026/09/11/what-is-rsv-and-who-is-eligible-for-the-vaccine/

seen at 09:36, 11 September in UK Health Security Agency.