Published: 2 March 2023
Revised: 27 February 2025
Safety Information
Monitoring communication
Update to original communication
24 February 2025
Jynneos (mpox vaccine) was granted provisional approval on 11 September 2024 (for 6 months). It is indicated for the prevention of mpox disease in adults aged 18 years of age and older at high risk of infection, see the data sheet for full indication.
There are now five suspected adverse reaction reports of pericarditis following Jynneos vaccination reported to the New Zealand Pharmacovigilance Database. Internationally, the USA has added myocarditis as a side effect of Jynneos vaccination to their prescribing information.
Vaccinators and healthcare professionals are reminded to advise vaccinees to seek immediate medical attention if they develop symptoms such as chest pain, shortness of breath or abnormal heartbeats following vaccination. Vaccinees presenting with symptoms should be urgently referred to specialists for diagnosis and treatment. Medsafe is working with the sponsor for Jynneos to update the data sheet with this advice.
Consumers and healthcare professionals are encouraged to report suspected adverse reactions to Medsafe and the Centre for Adverse Reactions Monitoring.
Original Communication
Reports of pericarditis following mpox vaccination
2 March 2023
Medsafe and the Centre for Adverse Reactions Monitoring (CARM) have received two reports of pericarditis suspected to be related to vaccination against mpox (monkeypox). Medsafe is encouraging people to report suspected adverse reactions including pericarditis following mpox vaccination.
Pericarditis refers to inflammation of the pericardial sac (inflammation of the bag-like membrane around the heart). There are many possible causes of pericarditis including viral infection. Pericarditis is treatable and outcomes are better the sooner treatment is started.
Other vaccines have previously been linked to pericarditis, including those used for COVID-19 (Comirnaty and Nuvaxovid).
- Advice for consumers and caregivers
- Information for healthcare professionals
- Regulator actions
- Reporting
Advice for consumers and caregivers
- In the first couple of weeks after vaccination, seek urgent
medical attention should you experience signs and symptoms
suggestive of pericarditis, these include:
- Chest pain (new onset or an increase in severity of existing chest pain), chest discomfort or heaviness
- Shortness of breath or difficulty breathing
- Chest pain that gets worse when coughing, lying down, or taking a deep breath
- Please discuss any concerns you have with your healthcare professional
- Please continue to report suspected adverse events to CARM
Information for healthcare professionals
- Vaccinators, continue to follow the informed consent process
- Advise patients to seek urgent medical attention should they experience signs and symptoms of pericarditis
- Refer to appropriate treatment guidelines, the goals of treatment therapy include relief of pain, resolution of inflammation, and prevention of recurrence
- Please continue to report suspected adverse events to CARM
Regulator actions
Medsafe is monitoring this safety concern.
Reporting
Please report any cases of pericarditis in patients who have been vaccinated against mpox. Please include information on:
- The time between vaccination and onset of pericarditis
- If the pericarditis occurred after the first or second dose
- How the pericarditis was diagnosed
- If any treatment was required
- If any other medicines are being taken
- Any relevant medical history
- Any tests performed and the results
Consumers and healthcare professionals are encouraged to report suspected adverse reactions to medicines to the Centre for Adverse Reactions Monitoring (CARM).
