Mpox (monkeypox) vaccines

Mpox vaccines

There are smallpox vaccines available in Australia that are thought to be effective against mpox. Vaccines can be given either before or after a person is exposed to the virus but vaccinating before exposure is recommended for the best protection.

If a person is exposed to mpox, receiving a vaccination within 4 days after first exposure to mpox will provide the highest chance of avoiding the disease.

People who have received smallpox vaccines can still catch mpox. Infection control measures should also be used to contain the spread of mpox.

There are 2 vaccines available for use in Australia:

1. JYNNEOS®
2. ACAM2000™

JYNNEOS® is the preferred vaccine for use in Australia based on its safety profile and because it is easier to administer.

Where JYNNEOS® is not suitable or not available, ACAM2000™ may be considered for healthy, non-pregnant adults.

As with any vaccine, vaccination with JYNNEOS® or ACAM2000™ should only take place after:

• a person and their healthcare professional have assessed the possible risks and benefits of receiving the vaccine, and
• the person has provided informed consent.

JYNNEOS® vaccine

JYNNEOS® is a modified vaccinia Ankara strain vaccine (MVA-BN) that contains a virus that has been altered so it cannot multiply in the human body. JYNNEOS® is manufactured by Bavarian Nordic.

It is given as 2 doses, at least 28 days apart for people 18 years and over.

The Australian Technical Advisory Group on Immunisation (ATAGI) has advised that that vaccination with JYNNEOS® in children can be considered, especially for people in high-risk groups aged 16 years and older, after discussing the risks and benefits with their vaccine provider.

JYNNEOS® can be injected subcutaneously (under the skin, preferably into the upper arm) or intradermally (into the outer layers of skin). However, intradermal administration of this vaccine is not recommended for anyone with a weakened immune system or a history of keloid scarring. It is also not preferred as a first dose for post-exposure vaccination.

The  Australian Government has made JYNNEOS® available immediately via a special emergency pathway under section 18A of the Therapeutic Goods Act 1989. This pathway ensures that vaccine is available urgently to deal emergencies and critical threats to public health.   

The Therapeutic Goods Administration has and will continue to review available information about quality and safety of JYNNEOS®, including reported adverse events and data provided by international regulators. 
JYNNEOS® is registered with both the US Food and Drug Administration and the European Medicines Agency.

Further information is available in the JYNNEOS® vaccine information sheet.

ACAM2000™ vaccine

ACAM2000™ is a live-attenuated smallpox vaccine that is also effective against mpox. ACAM2000™ is manufactured by Emergent BioSolutions.

Administration of ACAM2000™ requires specialised training and facilities.

ACAM2000™ is not suitable for:

• severely immunocompromised people
• people who are pregnant or breastfeeding
• people with cardiac disease or cardiac risk factors
• people with active eczema
• infants below 12 months of age.

ACAM2000™ is registered with the Therapeutic Goods Administration (TGA) for use in Australia. Visit the TGA website for more consumer information and product information about ACAM2000™.

Vaccine availability and access

There is a globally limited supply of the JYNNEOS® vaccine and high international demand.

The Australian Government, in conjunction with states and territories, has secured an initial supply of JYNNEOS® and is working with the manufacturer to secure more.

Given vaccine supply is limited, access to vaccines will initially be prioritised to support strong outbreak management, and this may include those who are:

• Close physical contacts of people infected with mpox, such as intimate partners and people who live in the same household.
• Population groups who might be at higher risk of exposure or further transmission, such as gay, bisexual, or other men who have sex with men who have a high number of sexual contacts or are travelling to countries where mpox is present, or those where mpox is more likely to result in serious illness.
• People whose occupations might put them at increased risk, including laboratory staff and healthcare workers.

States and territories are responsible for administration of the vaccine in their jurisdiction. This includes how and where it will be available and who will be prioritised to receive the vaccine. These decisions will be informed by local risk factors, such as local outbreaks and vaccine supply.

State and territories will provide further advice on how the vaccine can be accessed within their jurisdiction.

The Australian Technical Advisory Group on Immunisation (ATAGI) has recommended key risk groups for vaccination against mpox to support states and territories to prioritise their supply. This includes: 

• Post Exposure Prophylaxis (PEP): Anyone considered by public health authorities as a high risk mpox contact in the past 14 days.
• Gay, bisexual and other men who have sex with men who are at the highest risk of mpox infection. Proxy markers for increased risk of infection include:
  • Those living with HIV.
  • A recent history of multiple sexual partners, participating in group sex, or attending sex on premises venues.
  • Other proxy markers, such as recent sexually transmitted infection or those being advised to take HIV pre-exposure prophylaxis (PrEP) due to number of sexual partners. Whilst many people prescribed HIV PrEP are monogamous with a HIV positive partner, this category can also capture those with multiple partners who are at high risk.
  • Recommendation from other service providers, such as sexual health clinics.
• Sex workers, particularly those whose clients are in high-risk categories listed above.
• Anyone in the above risk categories who is planning travel to a country experiencing a significant outbreak, with vaccination recommended 4-6 weeks prior to departure.
• Anyone at greater risk of a poor clinical outcome from mpox infection, such as individuals with immunocompromise.
• Immunisation providers who are administering the ACAM2000™ smallpox vaccine.

When to get an mpox vaccine

The best time for people to receive the vaccine is before they are exposed to mpox. 

If a person is exposed to mpox, receiving a vaccination within 4 days after the first exposure, will provide the highest chance of avoiding disease. Vaccination between 4 to 14 days is likely to lessen the severity of disease.

Anyone at-risk who is planning to travel to a country experiencing a significant outbreak should be vaccinated 4-6 weeks before they depart to allow for maximum protection. 

Vaccine safety

Both of the available vaccines may result in mild or serious side effects:

JYNNEOS®

• common side effects include local injection site reactions (pain, redness, swelling and hardening ), muscle aches, headache, fatigue, nausea and chills. 

ACAM2000™

• a small bump at the vaccination site becomes a blister, then a scab
• possible permanent scar around the vaccination site
• the need for wound care around the vaccination site

Following vaccination, people who receive ACAM2000™ should also:

• avoid contact with other people at risk of serious adverse events, including immunocompromised people, people with HIV, to minimise risk of transmitting the vaccine to others
• avoid blood and organ donation for at least 30 days following vaccination
• women of child-bearing age need to avoid pregnancy for 28 days following vaccination.

If you are pregnant or breastfeeding

JYNNEOS® has not been studied in pregnant or breastfeeding women however, there are no expected safety concerns. ATAGI recommends that JYNNEOS® may be used during pregnancy, after a risk-benefit analysis.

ACAM2000™ vaccine cannot be used for pregnant and breastfeeding women.

If you are living with HIV

JYNNEOS® is considered safe for people living with HIV. However, lower immune response has been seen in HIV-infected people compared to healthy people.

ACAM2000™ vaccine cannot be used for those living with HIV.

Mpox and COVID-19 vaccines

ACAM2000 and mRNA COVID-19 vaccines are each associated with a rare risk of myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of the lining of the heart). The risk is highest in young adults, particularly males.

It is uncertain whether JYNNEOS® is associated with a risk of myocarditis or pericarditis.

ATAGI recommends that people at higher risk of myocarditis and pericarditis should consider separating their mpox vaccine dose and their mRNA COVID-19 vaccine dose by several weeks.

More information

Contact your local public health authority to find out if you should have a mpox vaccine.

Find out more about mpox.