Public advice on mpox vaccination
Mpox is a preventable infectious disease. Mpox vaccines can help prevent infection and slow the spread of mpox. Vaccination also helps to protect people from severe symptoms. This page provides important information about mpox vaccination, including the different types of vaccines available, who should be vaccinated and possible side effects. Since mpox vaccines are not readily available in all countries, check with your local Ministry of Health or the World Health Organization (WHO) country office website for the latest advice for where you live.
Mpox vaccines
The available mpox vaccines are:
| Name | How it is given and number of doses |
|---|---|
| MVA-BN Also known as Imvamune®, Imvanex® or Jynneos® | Injection below the skin in two doses, 28 days apart. Injection below the skin in a single dose.* Injection between layers of skin in two smaller “fractional” doses* |
| LC16m8 Also known as LC16-KMB®. | Injection with bifurcated (two-tipped) needle. Single dose. |
| ACAM2000 | Injection with bifurcated (two-tipped) needle. Single dose. Restricted use. |
* Health authorities might offer these schedules during an mpox outbreak to help reach as many people as possible.
Mpox vaccines are safe
Strict precautions are in place to help ensure the safety of mpox vaccines.
Before receiving validation from WHO and national regulatory agencies, mpox vaccines are subject to rigorous testing in clinical trials to prove that they meet internationally agreed benchmarks for safety. Recommendations on mpox vaccines and immunization are made by the WHO Strategic Advisory Group of Experts on Immunization (SAGE). They base their recommendations on a thorough review of all the available evidence.
WHO recommends MVA-BN and LC16m8 vaccines. Both these vaccines contain a weakened form of a related virus known as vaccinia virus which stimulates an immune response in the body. You may be offered one or the other vaccine depending on the country you live in.
ACAM2000 is currently licensed in the United States of America. Due to known side effects in some people, use of this vaccine is restricted. This webpage therefore only provides information about MVA-BN and LC16m8.
Priority groups for vaccination
Mpox vaccination is recommended for people at risk of contracting mpox, especially during an outbreak. Whether or not vaccination is advised depends on an individual’s personal risk level and national and local health policies.
It is important to use the available stocks to protect the people who are most at risk. Mass vaccination (i.e. vaccination of a large number of people in a country or a region regardless of their level of risk) is not currently recommended. This targeted approach currently prioritizes vaccination for the following people:
- People who have been in close contact with someone who has mpox (including children).
- People living in geographical areas with a high risk of exposure to mpox.
- Healthcare workers at risk of being exposed to mpox, including clinical laboratory and healthcare workers performing tests to diagnose mpox.
- Mpox outbreak response team members.
- People who have multiple sex partners, including men who have sex with men.
- Sex workers of any gender and their clients.
Note for travellers: Vaccination against mpox is not routinely recommended before travelling to a country where there is an mpox outbreak unless you are at risk of being exposed to mpox. If you are travelling to a place where there is an mpox outbreak, make sure you protect yourself to avoid exposure to mpox. If you have been in close contact with someone who has mpox, contact your local healthcare provider for further guidance on vaccination.
People at higher risk of severe disease and complications from mpox
The risk of severe mpox disease and complications – such as secondary infection, sepsis, pneumonia and encephalitis – is greater for pregnant women, young children (especially those who are malnourished or affected by other illness), and immunocompromised persons (for example, persons with untreated or uncontrolled advanced HIV infection and those who are on medical treatment that results in immune suppression). In areas with widespread transmission of mpox, these groups may also be prioritized for vaccination.
However, not all the vaccines are currently approved for these groups of people. They will only be offered the appropriate vaccine, depending on availability of vaccines and national guidelines.
The table below shows which vaccines are recommended for people in these groups.
| Recommended | Not currently recommended | |
| MVA-BN | Children aged 12 years and older. Children under 12 years, for “off-label” use*. Pregnant and breastfeeding women. Immunocompromised people or those on medical treatment that results in immune suppression. | |
| LC16m8 | Children from 1 year of age | Pregnant and breastfeeding women. Immunocompromised people, except those with well-controlled HIV |
* MVA-BN is not currently licensed for use in children under 12 years of age, however, available data about children show it is safe. Based on the safety data and the advice from WHO SAGE, MVA-BN may be used “off-label” for infants and children. This means the vaccine is recommended in emergency situations where the benefits of vaccination outweigh any potential risk. Its use must also be in alignment with national guidelines and approvals.
When to get vaccinated
Mpox vaccines can be given before or after exposure to someone with mpox or to the virus.
- Before exposure: to reduce the risk of becoming infected.
- After exposure: to reduce the risk of developing symptoms or severe disease.
If you are in a group for whom vaccination is recommended in your country, or were recently in close contact with someone who has mpox symptoms, contact your healthcare provider immediately for advice.
Where possible, people who have been exposed to someone who has mpox should be vaccinated within four days of exposure, or within 14 days if no symptoms develop.
Booster doses are not currently recommended.
Effectiveness of the vaccines
Available evidence shows that both MVA-BN and LC16m8 vaccines provide good protection for those who are fully vaccinated. Latest studies show that people vaccinated with two doses of the MVA-BN vaccine have 82% less chance, and those vaccinated with one dose have 76% less chance, of getting mpox than those who did not get the vaccine.
While some people may still develop mild mpox symptoms after vaccination, it will still give them protection against developing severe disease. People should continue to protect themselves wherever possible to reduce risk of infection and to protect others, even after being vaccinated.
Length of time to build immunity
It takes some time for immunity to develop after vaccination. The time it takes to develop maximum immunity depends on which vaccine is given:
- MVA-BN vaccine: two weeks after the second dose.
- LC16m8 vaccine: within four weeks of a single dose.
People should continue taking precautions during this period to avoid mpox. This also helps to protect those around you. Even after vaccination, it is important to continue protective behaviours in areas with known mpox transmission.
Possible side effects of the vaccine
As with any vaccine, some people may experience mild to moderate side effects after being vaccinated against mpox. This is a normal sign that the body is developing immunity. Not everyone will experience side effects after being vaccinated with MVA-BN vaccine.
Common side effects include pain, redness, swelling or itching at the injection site, muscle pain, headache, or fever.
Most side effects go away within a few days on their own. You can manage any side effects with rest, staying hydrated and taking medication to manage pain and fever, if needed.
People given LC16m8 vaccine will have a skin reaction called a “take” which occurs within two weeks of vaccination and then heals, sometimes leaving a small scar.
Reports of severe adverse events such as inflammation of the heart (called myocarditis or pericarditis) from these vaccines are very rare. It is very important to contact a healthcare provider if you experience chest pain or other symptoms of concern after vaccination.
Vaccination with a bifurcated needle
The LC16m8 vaccine is given using a ‘bifurcated needle’. It has two tips used to prick the arm so that the vaccine can enter the body effectively.
When giving the vaccine with a bifurcated needle, the vaccinator will use a multiple puncture vaccination technique, and a small drop of blood appears at the vaccination site.
The bifurcated needle was designed in the 1960s and was successfully used to vaccinate many millions of people during the smallpox eradication campaign.
After vaccination, a skin lesion (the “take”) will appear at the place on the body where the injection is given and the vaccination site needs to be cared for. The healthcare worker will give detailed instructions on how to do this.
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