Mpox vaccine - About the mpox vaccine

A vaccine is available to GBMSM who meet certain criteria and is offered on a case-by-case basis to help protect against mpox. The vaccine may also be offered to anyone who has close and intimate contact with people at higher risk of mpox in the GBMSM community. This includes people of any gender or sexual orientation.

You can get your mpox vaccine through sexual health services if you:

• have multiple sexual partners
• take part in group sex (or sex parties)
• visit sex venues (like saunas or backrooms), or
• have had a recent bacterial infection from sex, such as chlamydia or gonorrhoea, in the last year.

You may also be able to get the vaccine if you work in places where mpox could spread. This includes sauna staff or anyone who handles items or surfaces that may contain body fluids or skin cells.

You won’t get an invitation for the vaccine, but if you contact or visit a sexual health clinic and meet the criteria listed above, you should be offered the vaccine.

For more information on where to get the mpox vaccine, visit NHS 111 Wales website.

If you are a healthcare worker eligible for the mpox vaccine, please contact your occupational health department to check your vaccination status.

You will be offered the Modified Vaccinia Ankara (MVA) vaccine. This vaccine helps protect you against mpox (and smallpox).

There are two versions of this vaccine – Imvanex, made in Europe, and Jynneos, the US version. They are the same vaccine but come in different packaging. The version you get will depend on what’s available. Both are approved and work well.

The MVA vaccine contains a virus which has been modified so that it cannot grow in the human body. This vaccine was developed as a much safer form of the smallpox vaccine used widely in the UK and abroad until the 1970s.

The MVA vaccine cannot cause or spread smallpox or mpox.

As mpox is caused by a virus like smallpox, vaccines made to protect against smallpox can help prevent or reduce the risk of severe illness from mpox infection.

The MVA vaccine is offered through specialist sexual health services to those who are eligible.

The vaccine is available at the following clinics in Wales, by Health Board:

Aneurin Bevan University Health Board:  

• Royal Gwent Hospital

Betsi Cadwaladr University Health Board: 

• Wrexham & Flintshire: Wrexham Maelor Hospital
• Conwy & Denbighshire: Glan Clwyd Hospital
• Gwynedd & Anglesey: Ysbyty Gwynedd

Cardiff and Vale University Health Board:  

• Department of Sexual Health, Cardiff Royal Infirmary

Cwm Taf Morgannwg University Health Board: 

• Dewi Sant Hospital, Pontypridd

Hywel Dda University Health Board:  

• Penlan Clinic, Carmarthen

Swansea Bay University Health Board:  

• Neath Port Talbot Hospital

For the full list of sexual health services across Wales, visit the NHS 111 Wales website. 

Most people need two doses.

The second dose should be given at least 28 days after your first dose.

If you have previously been vaccinated against smallpox with the old (live) smallpox vaccine, you will only need a single dose of the MVA vaccine.

Once your course is complete, you do not need any more vaccines to protect you against mpox, unless you have a very weakened immune system and had your last dose more than two years ago.

The first dose of the vaccine should give you the highest level of protection about four weeks after you get it.

The vaccine may not prevent mpox completely, but if you do get it, your symptoms are likely to be milder.

! Two doses provide longer-lasting protection, which is why it is important to have both doses of the vaccine.

After two doses of the vaccine, most people develop a good level of protection against mpox. The second dose can be given at least 28 days after your first dose.

Even after two doses, you should continue to be aware of the risks and symptoms of mpox as no vaccine is 100% effective. You should also continue to get tested for STIs (sexually transmitted infections) regularly.

Very few people cannot have the mpox vaccination. You should not have the vaccine if you have had a serious (life-threatening) reaction to:

• a previous dose of the vaccine, or
• any ingredient in the vaccine.

The vaccine contains very small amounts of chicken protein and benzonase, as well as the antibiotics gentamicin and ciprofloxacin.

Speak to the person giving you the vaccine if you have had a serious allergic reaction to the vaccine or ingredients in the past.

If you are unwell, it is better to wait until you have recovered to have a vaccine. A cold or other minor illness is not a reason to delay your vaccine.

If you have a high temperature and have been in close contact with someone who has confirmed mpox, you may need to be checked for early signs of mpox infection.

If in doubt, discuss this with the person giving you your vaccination.

Tell your doctor or nurse about any medicines you are currently taking or have recently taken. You should also tell them about any other vaccines you have recently had. In most cases, you should be fine to have the vaccine.

The vaccine is safe for people living with HIV and those taking PreP. You can also have the vaccine at the same time as other important vaccines, including those which protect against human papilloma virus (HPV), hepatitis A, hepatitis B and gonorrhoea.

Like all medicines, vaccines can cause side effects. Most of these are mild and short-term, and not everyone gets them. Common side effects from the vaccine should only last a few days.

 Common side effects include:

• pain, redness, swelling, hardness or itching where the injection was given
• a headache
• muscle aches or joint pain
• feeling sick
• tiredness
• chills and fever, and
• loss of appetite.

If you feel faint after the vaccination, you should wait for 15 minutes before you drive.

If you get any of the side effects listed above, you can rest and take the normal dose of paracetamol (follow the advice in the packaging) to help you feel better. Do not drive or use machines if you are feeling unwell.

If the side effects last for more than a few days, you should speak to a healthcare professional.

If you have atopic dermatitis (a form of eczema), you may get a stronger skin reaction from the vaccine. This can include redness, swelling and itching. You might also get other general symptoms, such as a headache, muscle pain, and feeling sick or tired. Your skin condition may also flare up or worsen.

Side effects may be more common in people who have previously had a dose of the old (live) smallpox vaccine.

To find out more about vaccine side effects:

• Imvanex MVA vaccine

Visit the MHRA Products website. Type ‘Imvanex’ into the search box to find information and read the patient information leaflet.

•  Jynneos MVA vaccine

Visit JYNNEOS | FDA to find information and read the patient information leaflet online.

If you have any questions or concerns about side effects, you can ask the person giving you the vaccine, visit NHS 111 Wales or contact NHS 111 Wales by calling 111.

Rarely, people can have a severe reaction soon after vaccination, which causes breathing difficulties and may cause them to collapse. This is called an anaphylactic reaction, and it can also happen with other medicines and food. These reactions are extremely rare, affecting less than one in a million people. Staff who give vaccinations are trained to manage these reactions.

People who have an anaphylactic reaction can be successfully treated and usually recover within a few hours.

Vaccination is one of the most effective ways to prevent severe illness from mpox. No vaccine is 100% effective, so it is still important to know the signs and symptoms of mpox, even if you are vaccinated.

For more information about mpox, visit:

• NHS 111 Wales – Mpox
• Mpox – WHO

You should tell the doctor or nurse if you have atopic dermatitis, as the risk of side effects from the MVA vaccine may be higher.

If you have atopic dermatitis, you may get stronger skin reactions to the vaccine, such as redness, swelling, and itching. You might also have other side effects, like headache, muscle pain, or fatigue. Your skin condition may also flare up or worsen.

Yes, you can have the vaccine if you are HIV-positive. However, if you have a very weakened immune system, the vaccine may not protect you as well. Let your doctor or nurse know that you are HIV-positive.

It’s recommended to avoid high risk sexual activity until after your second dose.

If you are pregnant, think you may be pregnant or are planning to have a baby, talk to your doctor or nurse before having the vaccination. The MVA vaccine does not cause smallpox or mpox, so it cannot spread to an unborn child.

Mpox may be more severe during pregnancy, and there is also a risk of passing mpox to your baby. Your doctor or nurse will help you understand the benefits of the vaccine and any possible risks.

If you are breast feeding, you can have the vaccine. It is unlikely that the vaccine will pass into your breast milk.

If you do get mpox, there is a risk of passing the infection to your baby, and mpox may be more severe in small babies. Your doctor or nurse can help to explain the benefits of vaccination.

Mpox can be more serious in children, particularly those under the age of five, so the vaccine is recommended for children and babies if they need it. Vaccines using the MVA virus appear to work very well. They also have an acceptable safety record in small children, with side effects similar to other baby vaccines.

The MVA vaccine has also been given safely to a number of children in the UK who have had contact with a person with mpox.

The vaccine can be offered to children after an assessment by a healthcare professional.

The risk of mpox is low for most travellers. An mpox vaccine is not currently recommended for most people travelling to a country affected by mpox. Groups who are eligible for vaccination will be updated as more information becomes available.

If you are travelling to a country or area affected by an ongoing mpox outbreak, you should take special care to protect yourself by avoiding touch or sexual contact with anyone who is unwell or has a rash. For more information, visit NaTHNaC – Mpox.

To see the list of countries affected by mpox, visit the Travel Health Pro website. You can also check the GOV UK foreign travel advice web page to see if the country you are visiting is affected by mpox.

If you have recently visited a country affected by mpox, be aware of mpox symptoms. If you develop any spots, blisters or sores within 21 days of coming home, stay at home and call NHS 111 Wales or your GP for advice. Make sure you tell them your recent travel history.

You may be offered the vaccine if you have been in close contact with someone with mpox, depending on when you had contact with them.

The vaccine may help lower your risk of developing mpox or may make symptoms less severe if you do get it.

If you think you might be at risk, contact NHS 111 Wales by calling 111, or contact a sexual health service or your GP straight away.

If you are advised to have the MVA vaccine, you will be offered a single dose, ideally within four days of the close contact. However, the following people may have the dose up to 14 days after close contact.

• Children below the age of 5
• Pregnant women
• People with a very weak immune system