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Mpox vaccine - Mpox information for health professionals

The vaccine available is the Modified Vaccinia Ankara (MVA-BN) vaccine.  

The MVA-BN vaccine, originally designed for smallpox, offers a good level of protection against mpox. During the 2022 mpox outbreak, the vaccine’s effectiveness was estimated between 74-83%. The vaccine also helps reduce disease severity, with an estimated 67% effectiveness in preventing hospitalisation.  

The MVA-BN vaccine has been authorised for active immunisation against mpox in adults by the UK by the Medicines and Healthcare Products Regulatory Agency (MHRA). There are two versions of this vaccine: Imvanex, made in Europe, and Jynneos, the US version. They are the same vaccine (manufactured by Bavarian Nordic) but come in different packaging. 

The vaccine can be administered by the subcutaneous or intramuscular route (see immunisation procedures: Green Book chapter 4 (external site)). The preferred site is the deltoid region of the upper arm. 

The virus used in the vaccine is a replication-defective virus (also known as replication-incompetent virus). The virus used in the vaccine is also attenuated, so it cannot replicate in mammalian cells. It should be considered an inactivated vaccine. 

The MVA-BN vaccine is a black triangle vaccine and therefore subject to additional monitoring. This will allow quick identification of new safety information. Healthcare professionals are asked to report any suspected adverse reactions using the Yellow Card reporting scheme (external site). 

Dosing 

Most eligible people will require two doses. The second dose should be given at least 28 days after the first dose.  

If the MVA-BN course is interrupted or delayed, it should be resumed using the same vaccine, but the first dose does not need to be repeated. 

People who have previously been vaccinated against smallpox with the live smallpox vaccination will only require a single dose of the MVA-BN vaccine. 

Refer to the Green Book Chapter 29 Smallpox and mpox – GOV UK (external site) and the Welsh Medicines Advice Service (external Site) for further information. 

Occupational vaccination 

Most health and social care workers are at very low risk of mpox exposure and do not need a routine mpox pre-exposure vaccination. Staff working in specialist roles with frequent and prolonged exposure to orthopox viruses should be assessed by occupational health and offered vaccination if necessary. This includes: 

  • Laboratory workers who handle or culture pox viruses (such as mpox or genetically modified vaccinia), including those in highly specialist laboratories. 
  • Staff caring for in-patients with mpox in high consequence infectious disease (HCID) units, including those who clean areas where mpox patients have been cared for. 
  • Staff who regularly perform environmental decontamination around cases of mpox. 
  • UK healthcare and laboratory staff deployed to respond to an mpox outbreak or incident overseas. 
  • UK humanitarian aid workers going to live and work in close contact with the local population in areas affected by an mpox outbreak or incident overseas.    

Advice for people travelling to countries with an mpox outbreak 

Vaccination is not currently recommended for travellers. Current advice on avoiding mpox while travelling is available on the Travel Health Pro website: NaTHNaC – Mpox (external site).

Post-exposure vaccination for outbreak response 

The aims of post exposure immunisation are to prevent infection and reduce the severity of the disease in individuals who have been exposed to mpox.  

Post exposure vaccination should be considered for those with the highest exposure risks (this is defined in the contact tracing guidance for mpox – GOV.UK (external site)).

There is growing evidence that post-exposure vaccination has low effectiveness in preventing mpox infection. However, if given promptly it may have the potential to prevent infection and/or to reduce the severity of the disease. Individuals should be risk assessed by a Health Protection team and the vaccine should be prioritised for those most likely to benefit from it. For example, individuals very recently exposed to mpox or those at higher risk of severe disease following infection. 

Post-exposure vaccination of high-risk community or occupational contacts should ideally be offered within 4 days of exposure. However, it may be offered within 14 days in those at ongoing risk, or for those who are at higher risk of complications from mpox. For example: 

  • children (below the age of five years),  
  • pregnant women, and  
  • individuals with severe immunosuppression. 

Any exposure event may provide a chance to offer a first or second dose of the vaccine to individuals who have not yet been vaccinated. This applies to those eligible for pre-exposure vaccination, such as GBMSM at risk of mpox and certain health care workers. 

Refer to smallpox and mpox: Green Book, Chapter 29 (external site) and contact tracing guidance for mpox – GOV.UK (external site)  for further information. 

Co-administration 

The MVA-BN vaccine is a non-live vaccine, so it can be given with live vaccines and in people taking PrEP. It can also be given at the same time as the MenB, HPV, hepatitis A and hepatitis B vaccines. 

Guidance

Vaccination programme recommendations from the Joint Committee on Vaccination and Immunisation (JCVI) and Welsh Government policy can be found at the links below. 

Clinical resources and information

Patient group directions (PGDs) 

Vaccine PGD templates and Advisory Documents for Wales can be found on the Welsh Medicines Advice Service web page (external site) .  

Data and Surveillance

Page last reviewed: 9th October 2025