QUB Study Confirms UK Maternal RSV Vaccination Programme Protects Infants from Severe Respiratory Illness
A study involving researchers at Queen's University Belfast has confirmed that the UK's maternal Respiratory Syncytial Virus (RSV) vaccination programme effectively protects infants from severe respiratory illness, providing important real-world evidence for the expansion of the programme and offering significant implications for public health policy across Northern Ireland and the Republic of Ireland. The findings, published this month, demonstrate that vaccinating pregnant women against RSV provides meaningful protection to their newborns during the critical first months of life, when the virus poses the greatest risk.
Background
Respiratory Syncytial Virus — RSV — is one of the most common causes of respiratory illness in infants and young children. In most healthy older children and adults, RSV causes symptoms similar to a common cold and resolves without serious complications. But in infants, particularly those under six months of age, RSV can cause severe lower respiratory tract infections — bronchiolitis and pneumonia — that can require hospitalisation and, in the most serious cases, intensive care. RSV is the leading cause of hospitalisation in infants in the United Kingdom and Ireland, placing a significant burden on paediatric services during the winter months when the virus circulates most actively.
The development of effective RSV vaccines has been one of the most significant advances in vaccinology in recent years. For decades, RSV vaccination proved elusive — an early vaccine candidate in the 1960s actually made disease worse in some children, setting back the field for a generation. But advances in understanding of the virus's structure, and in particular the identification of the pre-fusion form of the RSV F protein as the key target for neutralising antibodies, led to the development of a new generation of highly effective vaccines.
The UK's maternal RSV vaccination programme, which offers vaccination to pregnant women during the third trimester, was introduced in 2023 following the approval of the Abrysvo vaccine by the Medicines and Healthcare products Regulatory Agency. The rationale for maternal vaccination is that antibodies produced by the vaccinated mother are transferred to the foetus across the placenta, providing the newborn with protection during the first months of life — precisely the period when RSV poses the greatest risk. The programme was the first of its kind in the world, and its real-world effectiveness has been closely monitored since its introduction.
Key Developments
The QUB-involved study, published in a peer-reviewed journal this month, provides the most comprehensive real-world evidence to date of the maternal RSV vaccination programme's effectiveness. The study analysed data from thousands of infants born to vaccinated and unvaccinated mothers across the UK, comparing rates of RSV-related hospitalisation, intensive care admission, and severe respiratory illness between the two groups.
The findings are striking. Infants born to vaccinated mothers showed a significantly lower rate of RSV-related hospitalisation compared to those born to unvaccinated mothers, with the protection particularly pronounced in the first three months of life — the period of greatest vulnerability. The study also found a reduction in the severity of RSV illness among infants who did become infected despite maternal vaccination, suggesting that the antibodies transferred from vaccinated mothers provide partial protection even when they do not prevent infection entirely.
The QUB researchers involved in the study have welcomed the findings as confirmation that the maternal vaccination strategy is working as intended and have called for the programme to be expanded and sustained. They have also highlighted the implications for the Republic of Ireland, where a maternal RSV vaccination programme has been under consideration but has not yet been introduced. The evidence from the UK programme, they argue, provides a strong basis for the HSE to move forward with a similar initiative.
Why It Matters
RSV is a significant cause of infant hospitalisation in Northern Ireland and the Republic, placing pressure on paediatric services — particularly in the winter months — that are already stretched. The Royal Belfast Hospital for Sick Children, the Children's University Hospital Temple Street, and Our Lady's Children's Hospital Crumlin all see significant numbers of RSV-related admissions each winter, and the burden on families whose infants require hospitalisation is considerable. A vaccination programme that can meaningfully reduce the rate of severe RSV illness in infants would have significant benefits for public health, for the health service, and for the families affected.
The study's findings are also significant for the broader question of maternal vaccination as a public health strategy. RSV is not the only pathogen for which maternal vaccination has been proposed as a means of protecting newborns, and the evidence from the RSV programme will inform decisions about other potential maternal vaccination initiatives in the future.
Local Impact
In Northern Ireland, the maternal RSV vaccination programme has been available since its introduction in 2023, and the QUB study's findings will be used to inform decisions about the programme's future development and expansion. The Public Health Agency of Northern Ireland has welcomed the study and has indicated that it will review the findings as part of its ongoing assessment of the programme's effectiveness. In the Republic, the HSE's National Immunisation Advisory Committee is expected to consider the study's findings as part of its deliberations on whether to introduce a maternal RSV vaccination programme, with a recommendation expected before the end of the year.
What's Next
The QUB researchers will present their findings at the European Society for Paediatric Infectious Diseases conference in September, where the study is expected to generate significant discussion among paediatric infectious disease specialists from across Europe. The UK Health Security Agency will use the study's findings to inform its annual review of the maternal RSV vaccination programme, which is expected to be published in the autumn. In the Republic, the HSE's National Immunisation Advisory Committee is expected to publish its recommendation on maternal RSV vaccination before the end of 2026, with a programme potentially beginning in time for the 2027 RSV season.
