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Research begins in North West London to tackle RSV infections in infants

Hospitals across London will play a vital role in a new respiratory virus study.

RSV (Respiratory Syncytial Virus) is one of the leading causes of hospitalisation in infants worldwide and affects 90% of children before the age of two. RSV often causes only mild illnesses, like a cold. However, for some babies, it can cause more severe illness such as bronchiolitis and pneumonia, resulting in hospital admission. In recent months, there has been a resurgence of RSV following the easing of COVID-19 public health measures.

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).

The study is evaluating the efficacy of Nirsevimab, a monoclonal antibody, in protecting against RSV hospitalisations worldwide. More than 20,000 infants across three countries (United Kingdom, France and Germany) will take part in the study, from August 2022 to March 2023.

In London, the study will run at:

  • Royal Free London NHS Foundation Trust
  • Barts Health NHS Trust
  • University College London Hospitals NHS Trust (UCLH)
  • King’s College Hospital NHS Foundation Trust
  • St George’s University Hospitals NHS Foundation Trust
  • Chelsea and Westminster Hospital NHS Foundation Trust
  • Northwick Park Hospital (London North West University Healthcare NHS Trust)
  • St Mary’s Hospital (Imperial College Healthcare NHS Trust)
  • Homerton Healthcare NHS Foundation Trust

"...I am doing something to support my baby’s immune system and support possible changes to healthcare for babies in the future..."

Gemma Dean from Basildon, Essex, whose six-week-old baby Hope is taking part in the study at Barts Health NHS Trust, said:

"As a paediatric nurse, I know the dangers of RSV. To know I am doing something to support my baby’s immune system and support possible changes to healthcare for babies in the future means so much and is why I didn’t hesitate enrolling into this study."


Dr Elizabeth Whittaker, Principal Investigator of the trial at Imperial College Healthcare NHS Trust, said:

"We're very proud to be able to offer this research opportunity to our patients and the wider community. RSV results in 1 in 6 hospital admissions in babies in the UK; being able to prevent this would be amazing.

"We need a large number of volunteers so we’re encouraging anyone interested in taking part to find out more and get in touch with any questions."


Dr Nilesh Agrawal, Principal Investigator of the trial at Chelsea and Westminster Hospital NHS Foundation Trust, said:

"At Chelsea and Westminster Hospital, we are excited to give our patients the opportunity to take part in this trial.

"Nirsevimab appears to be safe and effective in preliminary trials. If its benefit and tolerability is proved, we can adopt a broad universal immunization approach to reduce the impact RSV has on babies and health ecosystems. It will be one less virus to worry about."


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 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.

Nirsevimab is an investigational long-acting antibody aiming to protect all infants from birth entering their first RSV season with a single dose.

Find out more about the HARMONIE study.