Protect infants this RSV season

23 April 2025

Respiratory syncytial virus (RSV) is a highly infectious virus that is the most common cause of respiratory infections in children, with almost all unprotected children being infected at least once in their first 2 years of life. RSV bronchiolitis is one of the most common causes of hospitalisation in young infants and can occasionally result in death.  Signs and symptoms in infants include cough, rhinorrhoea, tachypnoea, fever, apnoea, difficulty feeding, with crackles and wheeze evident on auscultation. Patients are likely infectious until recovery, typically up to 8 days after symptoms appear, with transmission via direct contact, surfaces, and droplets.

There were 12,196 RSV notifications in 2024 (4,076 in infants under 2 years), and there have been 1,039 year to date in 2025. In South Australia (SA), infections usually increase in May and peak in July.

RSV Maternal Vaccination Program

• The National Immunisation Program (NIP) provides free maternal RSV vaccine (Abrysvo^®) in pregnancy from 28 weeks. This works by passively protecting the newborn infant from RSV for up to 6 months.

RSV Infant Protection Program (PDF 270KB)

An alternative approach to passive immunisation of infants is the use of long-acting monoclonal antibodies (mAbs). Beyfortus ^TM (nirsevimab) is a new mAb against RSV available for administration to infants in SA during the RSV season from 1 Apr to 30 Sept 2025. Beyfortus is recommended for:

• Infants less than 8 months of age in their first RSV season:
  • Unprotected infants (whose mother was not able to receive the maternal RSV vaccine), or
  • Whose mother was vaccinated with the maternal RSV vaccine less than 2 weeks prior to delivery, or
  • Infants with additional risk factors for RSV regardless of their mother’s RSV vaccination status.
    Refer to the Australian immunisation Handbook flowchart for guidance on which infants should receive nirsevimab in their first RSV season.
• Children less than 2 years of age with certain risk factors in their second RSV season.

Doctors are recommended to:

• Order the RSV maternal vaccine, Abrysvo, through the SA Health Vaccine Distribution Centre (VDC) in line with other NIP vaccines for use in pregnancy.
• Promote Abrysvo vaccine to all eligible pregnant people, emphasising your recommendation as a trusted health professional.
• Consider opportunities to co-administer the RSV vaccine with the recommended whooping cough (pertussis) and influenza vaccines, where appropriate in terms of timing during pregnancy.
• Ensure you provide the correct vaccine. There are two approved RSV vaccines for use in adults. Abrysvo available on the NIP is the only registered RSV vaccine approved for use in pregnancy.
• Order Beyfortus through the VDC. Beyfortus is available in two formulations, according to current infant weight:
  • Beyfortus 50mg for babies less than 5kg, and
  • Beyfortus 100mg for infants greater than 5kg.
    Generally, GP practices will require fewer 50mg doses compared to 100mg doses as most smaller infants will have received immunisation postnatally prior to discharge from hospital. Ordering though the VDC will ensure that the correct dosages are ordered.
• Please contact, during business hours, the VDC on (08) 7425 7139 if you have any queries related to Beyfortus supply, or the Immunisation Section, 1300 232 272, for program advice.

• Report any RSV vaccine and mAb you administer to the Australian Immunisation Register.
• See www.sahealth.sa.gov.au/rsv and the Australian Immunisation Handbook for more information.

For all enquires please contact the CDCB on 1300 232 272 (24 hours/7 days)

Dr Louise Flood – Deputy Director, Communicable Disease Control Branch