Advice for health professionals

JYNNEOS is the preferred vaccine for post-exposure preventative vaccination (PEPV) in NSW due to its favourable safety profile and ease of administration. If indicated, PEPV should be administered as soon as possible after presumed or confirmed exposure to a person with mpox, ideally within 4 days after last exposure, although administration up to 14 days can be considered as it may attenuate disease severity.

PEPV can be given to people who are identified as high and medium risk contacts who:

• have not received two doses of JYNNEOS vaccine, and
• have known or presumed exposure to a person with mpox, and/or
• have certain risk factors and recent experiences that might make them more likely to have been exposed to mpox and
• are asymptomatic at the time of presentation for PEPV.

Contacts who have not previously received a dose of JYNNEOS vaccine

For the purposes of PEPV, a single dose of 0.5mL (subcutaneous) is required for protection against contracting mpox infection and attenuating disease/symptoms. If mpox has not occurred and there is a significant ongoing risk of exposure, a second dose of JYNNEOS may be considered at least 28 days after the first dose as completion of a primary course for long-term protection.

The Australian Technical Advisory Group on Immunisation (ATAGI) recommendations have been updated to remove the age restriction; people of all ages who are at risk of exposure to mpox are recommended to receive mpox vaccination. Vaccination of child contacts can occur after a discussion with the treating clinician of the risks/benefits.

Contacts who have already received one dose of JYNNEOS vaccine

Contacts presenting for PEPV who have received a single dose of JYNNEOS vaccine should be offered a second dose if at least 28 days has passed since their first dose.

Contacts who have already received two doses of JYNNEOS vaccine

Contacts who have received two doses of the JYNNEOS vaccine do not require PEPV after being exposed to mpox. Currently, the Australian Technical Advisory Group on Immunisation does not recommend booster doses of the mpox vaccine for people fully vaccinated with 2 doses, including those who are severely immunocompromised.

Contacts who have previously had mpox

Recovery from infection (regardless of clade) likely confers protection from either clade of mpox. It is possible for individuals who have recovered from mpox to experience a reinfection, but this is thought to be rare, and the second infection is generally milder than the initial infection. Because of this, people who have recovered from mpox are not recommended to receive JYNNEOS vaccine doses at this time.

Contacts who are symptomatic for mpox

Vaccination given after the onset of signs or symptoms of mpox, after a diagnosis of mpox, or is not recommended or expected to provide benefit.

Accessing PEPV - advice for public health units

1. PHU is made aware of high/medium risk contact who has not previously been fully vaccinated and willing for PEPV.
2. Contact local publicly funded sexual health service to confirm JYNNEOS is available and arrange an appointment. It may be more appropriate for a child contact to be vaccinated at a specialist paediatric service such as the Sydney Children’s Hospital Network emergency department​, in discussion with the infectious diseases consultant on-call.
3. If a weekend or public holiday, contact other providers to determine if JYNNEOS is available:
   • NSW Biocontainment Unit – ID physician on-call 24/7 via Westmead Hospital switch
   • Kirketon Road Centre – open Saturday and Sunday mornings.
   • Other mpox vaccination providers – variable weekend hours and billing arrangements would need to be discussed with each practice.
4. If no existing vaccination provider is available, arrange delivery of JYYNEOS to a Local Health District (LHD) emergency department or other suitable site as per 'Ordering vaccine from the State Vaccine Centre' protocol below.
5. Vaccination provider to review for:
   • exposure history
   • health status/risk factors
   • prior vaccination with JYNNEOS.
6. Check meets PEPV criteria:
   • if agrees – medical officer/authorised nurse immuniser administers JYNNEOS vaccine, provide factsheet
   • if declines – ensure provided with contact factsheet.

Ordering vaccine from the State Vaccine Centre

Vaccine should only be ordered from the State Vaccine Centre when at-risk contacts are not able to access vaccine from an existing provider.

The process of ordering and administration of vaccine should be as follows:

• PHU staff to get PHU Director approval prior to ordering the vaccine.
• PHU orders from State Vaccine Centre.
• PHU to advise administering facility when to expect delivery (delivery of vaccine will come as a package of 20 vials).
• Administering facility advises PHU that delivery has arrived.
• Contact attends administering facility and is reviewed by medical officer or nurse practitioner and vaccine administered.
• Administering facility advises PHU that dose has been received by contact.
• Administering facility or PHU to record dose in the Australian Immunisation Register (local arrangement), if recipient consents.
• Remaining vials of vaccine to be refrigerated at 2-8°C in original package.

On the next business day, the PHU should arrange with the pharmacy to transport the remaining vaccine in its original packaging to a local authorised site, most commonly a sexual health clinic. Records of distribution must be kept in line with the state-wide protocol for JYNNEOS vaccine consent, supply and administration in NSW.