NCT04959734: BronchSTART

COVID-19 Impact on RSV Emergency Presentations

Recruiting now Last updated 5 January 2026

What this trial tests

trial in Bronchiolitis; Respiratory Syncytial Virus in 3,000 participants. Currently enrolling.

Timeline

25 June 2021

Primary endpoint
27 March 2026

27 March 2026

Quick facts

Lead sponsor	University Hospitals, Leicester
Status	Recruiting now
Study type	OBSERVATIONAL
Enrollment	3,000
Start date	25 June 2021
Primary completion	27 March 2026
Estimated completion	27 March 2026
Sites	1 location across United Kingdom

Conditions studied

• Bronchiolitis; Respiratory Syncytial Virus — all drugs for Bronchiolitis; Respiratory Syncytial Virus →

Sponsor

University Hospitals, Leicester

Who can join

Adults 0 to 2, any sex, with Bronchiolitis; Respiratory Syncytial Virus. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

Bronchiolitis is a very common winter disease that normally affects children less than one year of age. It is a common reason for parents and carers to bring their child to an Emergency Department (ED) and the frequent need for hospital admission means that paediatric units are at their capacity each winter.

During the COVID19 pandemic the virus that causes bronchiolitis (Respiratory Syncytial Virus; RSV) disappeared meaning this winter there have been virtually no cases of bronchiolitis in the United Kingdom. This phenomenon has been observed in many other countries around the world. Evidence from Australia suggests as restrictions such as social distancing for COVID19 are relaxed bronchiolitis returns, even in the summer. At the release of lockdown the return has been so dramatic in some areas of Australia the summer time numbers are above a typical winter. There is also evidence it may affect older children up to 2 years of age.

It is likely the Australian experience will be mirrored in the UK. The ability to track, anticipate and respond to a surge in bronchiolitis is important. There is a need to understand:

1. the onset of RSV spread at the earliest opportunity. This is important as some children are at higher risk of hospitalisation, intensive care admission or death if they contract RSV; knowing when to passively immunise these children is a public health priority.
2. whether the population at risk is a wider age range than normal and whether disease severity is greater as these will both effect service planning;

There are currently no existing studies or surveillance systems fully able to address these questions. This study will use staff in Emergency Department to report, in real time, case of bronchiolitis that they see and record essential, but non-identifying, information about them.

In 2022/23 the study evolved from a prospective surveillance study into a genomic analysis study with sites collecting positive respiratory samples for RSV genomic review.

In 2024/25 the study was amended in light of the introduction of the Bivalent Prefusion F Vaccine in Pregnancy in the United Kingdom to undertake a Vaccine Effectiveness study.

The main inclusion criteria remains the same but mothers who would have been eligible for the vaccine, and deliver an infant during the RSV season, were consented to obtain vaccination details so these could be linked to BronchSTART records.

Publications & conference data

3 peer-reviewed publications reference this trial (live from Europe PMC):

1. The clinical impact of serious respiratory disease in children under the age of two during the 2021-2022 bronchiolitis season in the United Kingdom and Ireland
   Williams TC, Marlow R, Hardelid P, Lyttle MD, et al · · 2023 · cited 1× · DOI 10.1101/2023.02.22.23285616
2. Features of an Aseasonal 2021 RSV Epidemic in the UK and Ireland: Analysis of the First 10,000 Patients
   Roland D, Cunningham S, Hardelid P, Lyttle MD, et al · · 2022 · DOI 10.2139/ssrn.3999396
3. Features of an Aseasonal 2021 RSV Epidemic in the UK and Ireland: Analysis of the First 10,000 Patients
   Roland D, Williams T, Lyttle MD, Marlow R, et al · · 2022 · DOI 10.2139/ssrn.4010901