A new vaccine aimed at protecting babies from a respiratory virus is being trialled at the Royal Free London.

RSV (Respiratory Syncytial Virus) is one of the leading causes of hospitalisation in all infants worldwide and affects 90% of children before the age of two. In recent months, there has been a resurgence of RSV following the easing of COVID-19 public health measures.

Nirsevimab has already been proven to be safe and the larger trial will now test its effectiveness. Babies up to 12 months old are eligible for the single jab, with virtual follow-up appointments.  If found to be effective, the new jab could have a major impact on the long term health of thousands of children worldwide.

RSV often causes only mild illnesses, like a cold. However, for some babies, it leads to more severe lung problems such as bronchiolitis and pneumonia.

More than 20,000 infants across the UK, France and Germany will take part in the study.

At the Royal Free London the study will run at two sites – the Royal Free Hospital, where the Principal Investigator will be Dr Shye-Wei Wong and at Barnet Hospital, where the Principal Investigator will be Dr Krishna Jada. 

Dr Wong said: “RSV bronchiolitis places a significant  healthcare and emotional burden on children and families all over the world every year. It also has a major financial impact on families while the babies are being treated in hospital and from managing long-term complications. Babies with chronic health conditions are more vulnerable to RSV and their families more severely affected.”

Dr Jada added: “Having a safe and effective agent to prevent severe RSV bronchiolitis illness and associated morbidity would not only have a major impact on the long term health and wellbeing of vulnerable babies but also help ease the pressures faced by healthcare providers over winter when services are particularly stretched.

“Nirsevimab has already been found to be safe and effective in preliminary trials so we are really pleased to be involved in the next stage of this study.” 

Professor Andrew Ustianowski, National Specialty Lead for Infection at NIHR Clinical Research Network, said: “This study, supported by the National Institute for Health and Care Research across more than 100 sites, provides the UK with the opportunity to lead the way in a disease which impacts infants globally.

“By carrying out this widespread study, we can help discover how babies can be protected from such a common, yet potentially debilitating virus. Previous smaller studies of the antibody injection being used has shown nirsevimab has a good safety profile in babies, which will hopefully provide parents with the confidence to take part in the study.”

The study will include newborn babies to babies 12 months old who are in, or are approaching, their first RSV season. It will last approximately 12 months. It includes a single in person visit with entirely virtual follow up. Participants will be randomly assigned into one of two groups. One group will receive the antibody dose, and in the other group no injection will be given. 

The ground-breaking HARMONIE study will take place at several London hospitals and is a collaboration between Sanofi, its partner AstraZeneca, and the National Institute for Health and Care Research (NIHR).

Find out more about the study by visiting the HARMONIE website. If you would like more information and would like to take part at Barnet Hospital or the Royal Free Hospital e-mail rf-tr.paediatricresearch@nhs.net