A safe smallpox vaccine, called Imvanex in the UK is being used for mpox (monkeypox) vaccination. Both viruses are orthopoxviruses from the same family (poxviridae).

How effective is the vaccine?


The vaccine is safe and current evidence suggests it will help to protect you from mpox and severe illness. Please get the vaccine if you’re invited for it. As with most vaccines, if you are immunocompromised (i.e. have a poor immune response to illnesses) it may take longer for the vaccine to work.

We will learn more about the vaccine as more people are given it.

How do I get the vaccine?


The vaccine programme is prioritising gay and bisexual men and other men who have sex with men, who meet one or more of the following criteria (in the previous 12 months):

  • You have had 10 or more sexual partners in the last year.
  • You are taking PrEP (pre-exposure prophylaxis), or having sex without condoms.
  • You have been diagnosed with a sexually transmitted infection (STI) in the last year.
  • You have group sex (including chemsex).
  • You visit sex-on-premises venues such as saunas, sex clubs or dark rooms.
  • You are doing sex work.
  • You have already had contact with a person with a confirmed diagnosis of mpox (monkeypox) (ideally within four days but up sometimes up to 14).
  • Or you are likely to meet any of these criteria in the near future.

The criteria applies to people living with HIV. Trans and non-binary people, and some cis women, are also eligible if they meet the above criteria.

Vaccine is available in England, Scotland, Wales, and Northern Ireland. Call your local sexual health clinic for more information.

If you live in England, you can find an mpox vaccination site via the NHS website. In London, you can also use the Sexual Health London clinic finder.

Will I need a second dose?


Second doses are now being offered to most people. The UK Health Security Agency (UKHSA) was initially prioritising first doses, to ensure everyone at risk of being exposed to mpox could have some immunity.

If you haven’t been contacted about a second dose two to three months after your first injection, get in touch with your local sexual health clinic.

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Second dose?

Can I get a post-exposure vaccine?


If you have recently been a close contact of a person with a confirmed case of mpox you might be eligible for a post-exposure vaccine. This would ideally be offered within four days of exposure but may be offered up to 14 days and could prevent an infection or make symptoms much milder.

Can I get the vaccine if I have already had mpox (monkeypox)?


At present, those who have already had mpox are not being called for a vaccine as they will already have some immune protection against mpox. However, they may be offered a booster in the future. These guidelines are currently in development and we will update this information when we know more.

If I have HIV should I be on the priority list?


Gay and bisexual men and other men who have sex with men, and who are living with HIV are eligible for the vaccine if they meet the criteria. If you are on effective treatment, with controlled HIV and a CD4 above 200, you are not considered to be more vulnerable to mpox.

Mpox can be more severe for those living with HIV who aren’t on HIV treatment, or have a CD4 count below 200. People at high risk of HIV are advised to get tested for the virus, along with anyone who tests positive for mpox.

What if I had a smallpox vaccine when younger?


Yes, if you have already had the smallpox vaccine, it is safe to have an additional vaccine. People who had a smallpox vaccine as a child or more than three years ago are still encouraged to come forward for the vaccine as their immunity will have waned.