Introduction of a new RSV passive immunisation from autumn 2025 (WHC/2025/029)

Issue date:

14 July 2025.

Status:

Action.

Category:

Public health.

Title:

Introduction of Nirsevimab passive immunisation against Respiratory Syncytial Virus (RSV) in at risk infants for upcoming 2025 to 2026 RSV season.

Date of expiry:

Not applicable.

For action by:

• Chief executives, health boards / trusts.
• Immunisation leads, health boards / trusts.
• Immunisation coordinators, health boards.
• Vaccination operational leads, health boards / trusts.
• Medical directors, health boards / trusts.
• Directors of primary care, health boards / trusts.
• Nurse executive directors, health boards / trusts.
• Chief pharmacists, health boards / trusts.
• Directors of public health, health boards / trusts.
• Executive Director of Public Health, Public Health Wales.
• Head Vaccine Preventable Disease Programme, Public Health Wales.
• Director of Vaccine Delivery, Vaccination Programme Wales, NHS Executive.
• Community paediatricians, health boards.
• Heads of midwifery, health boards / trusts.
• Midwifery teams, health boards.
• Secondary care paediatricians, health boards.
• Consultant virologists, health boards.
• Health protection teams, health boards.
• General Practitioner Committee, Wales.
• General practitioners.
• Digital Health and Care Wales.

Action required by:

July 2025.

Sender:

Professor Isabel Oliver,
Chief Medical Officer,
Health, Social Care and Early Years Group,
Welsh Government.

Government contacts:

Vaccination Division,
Welsh Government,
Cathays Park,
Cardiff.
CF10 3NQ.
Email: wg.vaccinationsprogrammeteam@gov.wales

Enclosures:

None.

Dear Colleagues,

Globally, RSV infects up to 90% of children within the first two years of life and frequently reinfects older children and adults. Infants under one year of age and the elderly are at the greatest risk of hospitalisation with more severe RSV. The clinical significance of RSV in infants is that it can cause bronchiolitis, which leads to the inflammation of the small airways and significant breathing difficulties.

In 2010 the Joint Committee on Vaccination and Immunisation (JCVI) recommended a passive immunisation programme using a monoclonal antibody treatment called Palivizumab for use in very high-risk premature infants with conditions affecting the lungs or heart, and children with impaired immune systems. This programme is relatively labour intensive and requires, on average, five doses to be given across the season, but can in some cases require up to seven doses. The UK Green Book's Chapter 27a provides guidance to clinicians on dose schedules and eligibility. There are around 120 neonates who currently receive this treatment per year across Wales.

More recently, as part of the considerations around the establishment of an RSV vaccination programme, the JCVI has provided further advice on the selective RSV neonate programme in its online minutes on box.com. The committee now supports a change to the product used, recommending Nirsevimab instead of Palivizumab, due to its higher efficacy, subject to it being procured at a cost-effective price. The JCVI also advised an expansion to the eligibility for the neonate programme, offering Nirsevimab to all infants born at <32 weeks.

I am therefore writing to inform you that the Welsh Government has accepted the advice from the JCVI to implement a product change to Nirsevimab, which has now become available for the next RSV season, expected in October 2025, and to expand the existing RSV high-risk selective monoclonal antibody immunisation programme.

This new product will replace the existing product (Palivizumab) and the eligibility for the treatment will be expanded to include all pre-term infants born <32 weeks gestation, who are entering their first RSV season, alongside maintaining the programme for the existing groups.

This letter is aimed at health professionals who will deliver the RSV high-risk selective monoclonal antibody immunisation programmes in Wales. I encourage you to share this guidance with all those involved in delivering the programme in your area.

Changes to eligibility

Eligibility for the selective RSV monoclonal antibody programme will therefore include:

• preterm infants born <32 weeks who are entering their first RSV season
• the existing eligible groups from the previous iteration of this programme as indicated in the Green book's Chapter 27a

Programme start date

Planning for these changes should commence immediately and supplies should now be sourced for the incoming RSV season. Administration should commence for the expanded cohort to begin immunising, ideally from September 2025, but in line with the guidance in the Green Book.

Product supply

Sanofi in partnership with AstraZeneca has developed a new long acting monoclonal Beyfortus® (Nirsevimab) for passive immunisation against RSV infection and disease. Nirsevimab was licensed by the Medicines and Healthcare products Regulatory Agency (MHRA) on 9 November 2022. There is no central contract for this product. The list price will be flat across both 50mg and 100mg strength pre-filled syringe.

Beyfortus® (Nirsevimab) is marketed by Sanofi UK and Ireland (customer services: 0800 854 430) and can be ordered from Phoenix Healthcare Distribution Ltd.

Funding and service arrangements

The current selective treatment using Palivizumab is delivered through health boards in hospital settings. Most hospitals run outpatient clinics to deliver this treatment.

Operationally, the delivery arrangements for immunising infants with the new product, Nirsevimab, are expected to stay the same, with outpatient clinics offering to those eligible born before the RSV season.

The recommended dose of Nirsevimab is a single dose of 50 mg administered intramuscularly for infants with body weight less than 5kg and a single dose of 100 mg administered intramuscularly for infants with body weight of 5kg or more.

For the initial launch, the 50mg will be in a UK pack and the 100mg will be in a French pack with a supporting UK PIL (Patient Information Letter) and HCP (Health Care Professional) letter detailing the reasons for this. The 100mg pack will be available in a UK pack later in the season.

RSV paediatric disease incidence is expected to peak in late November or December, with prevalence rising through October and falling by the end of February. Nirsevimab is licensed as giving six-months protection. Use should begin from the second half of September for both cohorts. Pre-season catch-up administration to eligible children coming into their first season should ideally be completed by mid-October.

Whilst the new product in use carries a higher dose cost, there are some savings from the reduction in the amount of doses required, which are expected to offset this amount, though additional recurrent funding will be sent to health boards to support the offer to the expanded cohort. Health board finance directors will be issued with a letter in due course.

Further changes to this programme will be considered in the future, based on emergence of new products or additional information that may become available.

Information for healthcare professionals and eligible individuals

The RSV chapter of the Green book, which contains information about the use of Nirsevimab, is expected to have further revisions, so healthcare professionals should continue to consult this document for the latest advice.

Programme support will be available through the National Strategic Clinical Network for Maternity and Neonatal Services Team within NHS Wales Performance and Improvement.

Communications and engagement

A joint four nations communications approach is being devised with an announcement planned for mid July 2025

Surveillance and reporting

SNOMED procedure code advised for the recording of the monoclonal antibody immunisation Nirsevimab:

Programme:

• NHS RSV Passive Immunisation Programme.

Procedure name:

• Administration of respiratory syncytial virus immune globulin, human (procedure).

Procedure code, SNOMED:

• 117089007.

I would like to take this opportunity to thank everyone involved in this important programme in Wales. New RSV vaccines and monoclonal antibodies are protecting more babies and older adults from becoming seriously ill. The expansion of the programme outlined in this letter provides us with an opportunity to protect this vulnerable cohort better and increase the protection by expanding to further preterm infants. I am extremely grateful for the work and commitment shown to the programme.

Yours sincerely,

Professor Isabel Oliver
Chief Medical Officer.