Uptake of the respiratory syncytial virus (RSV) vaccine during pregnancy is not linked to increased risk of adverse perinatal health outcomes among vaccinated women, according to research at City St George’s and published in BMJ Open.
Published
This first of its kind study, in collaboration with the University of Cambridge, provides a holistic view of how age, ethnicity, and socioeconomic status influence vaccine uptake, with implications for infant health.
The authors note, however, that the study was not designed to assess vaccine safety in depth, and further research is needed.
RSV is a major cause of infant morbidity and mortality. In the UK, it accounts for approximately 33,500 infant hospitalisations in children under five years old, and 20-30 deaths annually. RSV infects up to 90% of children within their first two years of life and frequently reinfects older children.
The RSV vaccine is expected to prevent up to 5,000 hospitalisations and 15,000 emergency department visits annually in the UK, reducing the risk of severe bronchiolitis by 70% in the first six months of life.
The study found that older women, those from higher socioeconomic backgrounds, and white ethnic groups were more likely to receive the vaccine. In contrast, uptake was lower among women of an ethnic minority and those from deprived areas, which is a pattern consistent with other maternal vaccines such as for flu and COVID.
As of August 2025, over two million individuals (337,000 pregnant women) in England have received the RSV vaccine, yet uptake remains uneven, with London reporting the lowest coverage nationally.
Dr Mohammad Sharif Razai, lead researcher at the University of Cambridge who was part of the City St George’s Population Health Research Institute, said:
Concerns about higher rates of preterm birth associated with RSV vaccines were raised in early clinical trials. Despite being approved by the EU for use in pregnancy in 2023, its implementation varies. For example, in France it is recommended between 32 and 36 weeks’ gestation, while the UK Joint Committee on Vaccination and Immunisation (JCVI) recommends receiving one dose of RSV vaccine in every pregnancy from 28 weeks’ gestation.
This variation of implementation reflects differing view on the safety of this vaccine, corresponding to the study authors assertion that targeted interventions are needed to inform communities where uptake is at its lowest.
Professor Asma Khalil, Professor of Obstetrics and Maternal Medicine at City St George’s School of Health and Medical Sciences, said:
The study points to the need for further research to assess vaccine safety in depth, with deeper understanding on how to create public health interventions that improve vaccine delivery and awareness.