A vaccine given during pregnancy is significantly cutting hospital admissions among newborns with respiratory syncytial virus (RSV), with UK health officials reporting a decrease of more than 80 per cent. The jab, provided to pregnant women from 28 weeks of gestation since 2024, protects babies from birth by enhancing maternal immunity and transferring immunity through the placenta. A major new study analysing nearly 300,000 births across England between September 2024 and March 2025 has shown the vaccine’s “excellent protection” during the period when infants are particularly susceptible to the virus. RSV affects roughly half of all newborns and remains one of the primary reasons of hospital admission in babies under one year old, with more than 20,000 serious cases recorded annually across the UK.
How the immunisation protects at-risk babies
RSV, or respiratory syncytial virus, is a common respiratory infection that affects roughly half of all newborns during their first few months of life. The virus can vary from causing mild cold-like symptoms to triggering severe chest infections that cause babies to struggle to breathe and feed. In the most serious cases, the inflammation in the lungs becomes life-threatening, with small numbers of infants dying from the infection each year. Dr Conall Watson, national programme lead for RSV at the UK Health Security Agency, emphasises the deeply distressing nature of serious RSV infections: “In babies with severe infections you can see their chest and lungs working hard, as they try to pull enough oxygen in. This is extremely frightening as a parent, frightening with good reason.”
The pregnancy vaccine operates by stimulating the mother’s body’s defences to produce protective antibodies, which are then transferred to the foetus through the placenta. This maternal immunity provides newborns with immediate protection from the moment of birth, precisely when they are most vulnerable to RSV. The latest research shows that protection reaches approximately 85% when the vaccine is administered at least four weeks before delivery. Even shorter intervals between vaccination and birth can still provide meaningful protection, with evidence suggesting that a fortnight’s interval is sufficient to shield babies delivered prematurely. Dr Watson advises pregnant women to receive the vaccine on schedule, whilst noting that protection can still occur even if administered later in the third trimester.
- Nearly 85% protection when vaccinated 4 weeks before birth
- Maternal antibodies transferred through the placenta protect newborns from birth
- Coverage possible with two-week gap before early delivery
- Vaccination during third trimester still offers significant protection for infants
Strong evidence from recent research
The effectiveness of the RSV vaccine administered during pregnancy has been established through a extensive research programme carried out throughout England, analysing data from nearly 300,000 babies born between September 2024 and March 2025. This represents approximately nine out of ten of all births during that six-month timeframe, providing robust and representative evidence of the vaccine’s actual performance. The study’s conclusions have been supported by the UK Health Security Agency as showing “excellent protection” for newborns during their earliest and most vulnerable period. The scope of this study gives healthcare professionals and prospective parents with confidence in the vaccine’s established performance across different groups and contexts.
The results paint a compelling picture of the vaccine’s ability to protect. More than 4,500 babies were admitted to hospital with RSV throughout the study period, with the great majority being infants whose mothers had not been given the vaccination. This stark contrast emphasises the vaccine’s critical role in preventing serious illness in newborns. The decrease in hospital admissions surpassing 80 per cent represents a substantial public health milestone, helping to prevent thousands of infants from experiencing the alarming and potentially severe symptoms linked to severe RSV infection. These findings reinforce the importance of the vaccination programme introduced in the UK in 2024.
Research approach and coverage
The research reviewed birth and hospitalisation records from England over a six-month period, capturing data on approximately 90% of all births during this timeframe. By examining around 300,000 babies born to both vaccinated and unvaccinated mothers, researchers were in a position to determine clear comparisons of RSV infection rates and hospitalisations. The substantial sample size and comprehensive nature of the data collection ensured that findings were statistically robust and indicative of the general population, rather than individual cases or small subgroups.
The study specifically tracked hospital admissions for RSV among infants born to mothers who had been given the vaccine at varying intervals before delivery. This allowed researchers to identify the shortest interval needed between vaccination and birth for best possible protection, as well as to determine whether protection remained meaningful with briefer timeframes. The methodology measured real-world outcomes rather than experimental conditions, providing practical evidence of how the vaccine functions when delivered across varied healthcare environments and patient circumstances throughout pregnancy’s final trimester.
| Key Finding | Impact |
|---|---|
| Nearly 85% protection with four-week vaccination interval | Optimal protection achieved when vaccine given one month before delivery |
| Over 80% reduction in newborn hospital admissions | Thousands of infants prevented from serious RSV-related illness annually |
| Vast majority of hospitalisations in unvaccinated mothers’ babies | Clear evidence of vaccine efficacy in preventing severe infection |
| Protection possible with two-week pre-birth interval | Meaningful safeguard even for early deliveries and shorter vaccination windows |
Understanding RSV and the threats
Respiratory syncytial virus, typically known as RSV, is one of the leading causes of hospital admission in infants under one year of age across the United Kingdom. The virus affects approximately half of all newborns during their early months of life, with severity varying dramatically from minor cold-type symptoms to severe, life-threatening chest infections. More than 20,000 babies require intensive hospital care for RSV annually in the UK alone, placing enormous strain on paediatric wards and neonatal units during peak seasons.
The infection triggers inflammation deep within the lungs and airways, making it extremely challenging for vulnerable newborns to breathe and feed effectively. Parents often witness their babies visibly struggling, their chests heaving as they attempt to draw enough air into their damaged lungs. Whilst most infants recover with palliative treatment, a small but significant group succumb from RSV complications yearly, making immunisation programmes a critical public health imperative for defending the youngest and most at-risk people in our communities.
- RSV triggers lung inflammation, resulting in severe breathing difficulties in babies
- Nearly 50% of infants contract the infection during their first few months alive
- Symptoms span from mild colds to serious chest infections that threaten life requiring hospitalisation
- More than 20,000 UK babies need serious hospital treatment for RSV each year
- Few babies die from RSV related complications each year in the UK
Take-up rates and expert recommendations
Since the RSV vaccine programme began in 2024, health officials have stressed the importance of pregnant women getting their jab at the ideal time for peak protection. Dr Conall Watson, lead for the national programme for RSV at the UK Health Security Agency, has stressed that the timing is essential for ensuring newborns benefit from the strongest possible immunity from birth. Whilst the study demonstrates that vaccination performed at least four weeks prior to delivery delivers approximately 85% protection, experts advise women to get their vaccine as soon as feasible from 28 weeks of pregnancy onwards to enhance the antibodies passed to their babies via the placenta.
The messaging from health authorities remains clear: pregnant women ought to prioritise vaccination during their final three months, even if circumstances mean they cannot get vaccinated at the optimal time. Dr Watson has provided reassurance to pregnant women that protection is still achievable with shorter intervals between immunisation and delivery, including even a fourteen-day window for those delivering slightly early. This adaptable strategy acknowledges the realities of pregnancy and childbirth whilst ensuring strong protection for at-risk infants during their most critical early months when RSV poses the greatest risk of serious illness.
Regional differences in vaccination
Whilst the RSV vaccine programme has been rolled out across England, uptake rates and implementation timelines have differed across various areas and NHS trusts. Some areas have attained higher vaccination coverage among qualifying expectant mothers, whilst others remain focused to boost understanding and access to the jab. These regional differences reflect differences across healthcare infrastructure, engagement approaches, and community involvement initiatives, though the national data demonstrates robust and reliable protection regardless of geographical location.
- NHS trusts launching diverse outreach initiatives to reach expectant mothers
- Geographic variations in vaccine uptake rates throughout England necessitate strategic intervention
- Community health services adapting programmes to meet community needs and circumstances
Practical implications and parental perspectives
The vaccine’s impressive effectiveness provides real advantages for families across the United Kingdom. With over 20,000 babies admitted to hospital annually due to RSV before the launch of this safeguarding intervention, the 80% reduction in admissions means thousands of infants spared from severe infection. Parents no longer face the upsetting situation of seeing their babies struggle for breath or difficulty feeding, symptoms that mark severe RSV infections. The vaccine has markedly changed the landscape of neonatal respiratory health, giving expectant mothers a proactive tool to protect their youngest infants during those crucial first weeks.
For families like that of Malachi, whose severe RSV infection resulted in profound brain damage, the vaccine’s accessibility carries profound emotional significance. His mother’s support of the jab emphasises the transformative consequences that treatable infection can inflict on young children and their families. Whilst Malachi’s experience precedes the vaccine programme, his story resonates powerfully with parents now offered protection. The knowledge that such significant complications—hospital stay, oxygen dependency, neurological damage—are now mostly preventable has offered substantial reassurance to pregnant women during their third trimester, changing what was once an unavoidable seasonal threat into a manageable health risk.