UK Research: RSV Vaccine Protects Newborns Against Lung Infections

A major study in the United Kingdom has revealed that respiratory syncytial virus (RSV) vaccination during pregnancy cuts the risk of infants being hospitalized for severe lung infections by more than 70 percent. The evidence supports maternal immunization as a decisive tool to safeguard newborns in the earliest and riskiest stages of life.

Researchers analyzed real-world data following the introduction of the maternal RSV shot during the 2024-2025 RSV season. This approach provided a clear demonstration of how protective immunity delivered before birth can lead to dramatic reductions in infant hospitalizations.

RSV and its threat to infants

RSV is a common viral infection that frequently affects the noses, throats, and lungs of infants and young children. While most recover without severe symptoms, the youngest babies, especially those under six months, can experience bronchiolitis and pneumonia requiring urgent hospital care.

Transmission is easy: the virus spreads through droplets and survives for long periods on surfaces, making it a particular challenge in nurseries and crowded settings. Globally, RSV remains the top cause of childhood hospitalization for respiratory illness.

Did you know?
RSV was first discovered in chimpanzees, not humans, and only later recognized as a leading cause of child respiratory hospitalizations worldwide.

How maternal vaccination works

The success of the RSV vaccine is rooted in the natural process of antibody transfer from mother to fetus. When a pregnant woman is immunized, protective antibodies are produced and cross the placenta, especially in late pregnancy, offering passive immunity to the newborn.

This transfer is most effective in the third trimester, as the placenta’s special receptors transport the mother's immunoglobulin G (IgG) antibodies into the fetal bloodstream. As a result, the baby arrives with RSV-specific antibodies ready to neutralize the virus until its own immune system can mature.

Study findings: Dramatic drop in hospital admissions

The UK research tracked 537 infants admitted to hospitals in England and Scotland during the 2024-2025 RSV season. Among them, 391 tested positive for RSV. The greatest protection was observed when mothers received the vaccine more than two weeks before delivery; infant hospitalizations dropped by 72 percent compared to those born to unvaccinated mothers. Even when given at any point in pregnancy, the vaccine led to a 58 percent decline in admissions for lung infections.

Analysis revealed that 41 percent of mothers of healthy, RSV-negative babies had received the vaccine, versus just 19 percent among mothers whose babies were hospitalized with RSV. These numbers make a strong case for integrating the RSV vaccine into routine antenatal care.

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Shaping the future of prenatal care

Health officials in the UK and beyond are weighing how these findings could reshape prenatal care standards. By reducing the number of infants needing hospital care for respiratory illness, maternal RSV immunization could relieve pressure on pediatric wards, cut healthcare costs, and improve early childhood outcomes.

Public health experts recommend vaccination for pregnant women between the late second and third trimesters to optimize antibody transfer. While safety and long-term effects remain under close watch, this study offers timely real-world evidence to inform national immunization policies.

Next steps and global impact

If adopted widely, maternal RSV vaccination could make significant improvements in infant health on a global scale, especially in areas with high RSV disease burdens. Ongoing surveillance and further policy development may help ensure more newborns receive this essential protection from the very start.