Major trial involving Welsh researchers reports 83% reduction in infant hospitalisations thanks to new treatment

The HARMONIE study, which launched in Wales at Noah’s Ark Children’s Hospital at the end of 2022 and is supported by Health and Care Research Wales, has reported new data in its pursuit of an effective treatment for Respiratory Syncytial Virus (RSV).

RSV is extremely common in babies and children, is the leading cause of hospitalisation in infants and can be life-threatening.

The study administers a new antibody treatment, nirsevimab, by a jab in the thigh to healthy babies up to 12 months old. Participants in the study are randomly assigned to one of two groups, one receiving the treatment and another which is given standard care.

The HARMONIE study team has reported an 83% reduction in hospitalisations due to RSV in infants under 12 months who received the single dose or nirsevimab compared with infants who received no RSV intervention during the 2022-23 RSV season.

The trial recruited more than 8,000 infants across the United Kingdom, France and Germany. Globally, in 2019, there were approximately 33 million cases of acute lower respiratory infections leading to more than three million hospitalisations. It was estimated that there were 26,300 in-hospital deaths of children younger than five.

Investigator and Health and Care Research Wales Specialty Lead for Children and Young People, Dr Philip Connor, said:

We're delighted that the Noah's Ark Children's Hospital for Wales was able to participate in such an important study.  This vaccine has the potential to protect many young children from serious respiratory disease."

Dr Nicola Williams, National Director of Support and Delivery at Health and Care Research Wales, said:

These findings are very encouraging and demonstrate the crucial role of research in saving and improving lives. Health and Care Research Wales is proud to participate in HARMONIE and to offer Welsh parents the opportunity to help not only their own child but also help improve outcomes for others by being part of research.”

Spread by coughing and sneezing, RSV affects about 20,000 infants in Wales every year and causes a mild, cold-like illness most of the time. However, in some cases it can lead to more severe lung problems such as bronchiolitis and pneumonia.