Monkeypox (Mpox) – FAQ

It was first discovered in 1958 in laboratory monkeys, hence the previous name. However, it is not certain that monkeys are the main reservoir (carrier) of the virus. According to the latest findings, these are more likely to be African rodents.

Since May 2022, there has been a major outbreak outside the African continent. Particularly countries in Europe and North America have been affected, including Belgium.

VACCINATION BEFORE A RISK CONTACT: PREVENTIVE VACCINATION

Until the end of 2022, persons belonging to a risk group for mpox could be vaccinated preventively. The Flemish government has decided to end the preventive vaccination campaign against mpox as of 2023. This means that as of today it is no longer possible to get a vaccine against mpox. Exceptions are persons who already received a first vaccination against mpox in 2022; they can still receive their second vaccination. In this case, please contact ITM medical secretariat as soon as possible by calling +32(0)3 247 66 66.

Current contraindications to vaccination:

• Persons who have already experienced mpox.

• Persons with symptoms suggestive of mpox or acute infection with fever.

• Persons under 18 years of age (unless in exceptional cases).

• Persons allergic to the vaccine or any of its components: chicken protein, benzoase, gentamicin, ciprofloxacin. 

Administration of second dose of vaccine

Between the first and second vaccination against mpox, there should be an interval of at least 28 days. If you were already given the first vaccine intradermally (this concerns vaccinations from early September to 24 November 2022), the second vaccination will be given by the subcutaneous method on days 28-35.

VACCINATION AFTER A RISK CONTACT: POST-EXPOSURE VACCINATION

The following persons may receive a vaccine within 4 days of risk exposure to mpox:

• Persons with very-high-risk contact.

• Persons with a high-risk contact and an increased risk of serious infection.

• Healthcare personnel after a high-risk contact without adequate protection.

Only in rare cases do we consider vaccination between 4 and 14 days after high-risk exposure, namely when the person is also at increased risk of a severe course. This is assessed by the doctor at the vaccination centre.

By vaccination after risk exposure, we try to prevent infection with mpox and/or severe symptoms. However, data on the efficacy of this are still limited. Getting a vaccine after exposure is therefore no guarantee that you will not develop the disease. Therefore, it remains important to be alert for symptoms and follow the measures for very high-risk contacts (see 'What should I do in case of close contact with an infected person?').

If you are eligible for a vaccine after a high- or very-high-risk contact, it is best to contact your HIV reference centre urgently. In Antwerp, you can contact ITM at +32(0)3 247 66 66..

See the current epidemiological situation:

• European Centre for Disease Prevention and Control

• Sciensano

These skin lesions can be (red) spots, pimples, blisters or suppurative bumps, which finally heal after scabs have formed. These skin lesions can occur anywhere on the body and are sometimes painful. They are often found at the site of infection, especially around the anus, on the penis or in the mouth. These skin lesions can also occur without fever or flu-like syndrome.

We also see less classic presentations, such as people who have little or no skin lesions or who only have local symptoms, such as an inflammation of the throat, the anus or the urethra.

• direct contact with skin lesions that contain a lot of virus. For example, through prolonged skin-to-skin contact or sexual contact.

• contact with body fluids or mucous membranes of an infected person. In infected patients, we often find high concentrations of virus in the saliva and anus, but also in the semen sometimes.

• spreading of saliva droplets. This is possible, but probably less efficient.

• (in theory) transmission via contaminated surfaces or linen (such as bedding or towels).

In the current outbreak in Europe, for the time being, mainly men who have sex with men (MSM) are infected. Sexual contact appears to pose the greatest risk of infection, more so than skin-to-skin contact. Kissing also seems to be a risk exposure. Individuals who have multiple sexual partners are at greater risk of contracting the disease.

The samples must be taken in protective circumstances. To avoid contamination, it must be done in a separate room by a care worker wearing protective clothing.

• you've developed unexplained skin lesions with vesicles or skin lesions around the anus and you either:

  • are a man who had intimate contact with one or more men within the last few weeks;

  • have been in West or Central Africa.

• you've had close contact with someone infected with mpox in the last few weeks and you either:

  • developed a fever;

  • developed skin lesions;

  • have complaints of inflammation of the throat, anus or urethra.

If you suspect you have mpox, you should contact a centre where you can be tested as soon as possible. To prevent further infection of other people, you should go into isolation at home beforehand.

The ITM outpatient clinic can be reached on weekdays from 9am to 5pm on +32(0)3 247 66 66. If you live outside Antwerp, you can contact the emergency department of a hospital with an infectious diseases specialist on site travel-clinics / yellow-fever-vaccination-centres.

Always contact the health care providers before visiting the clinic. This allows them to prepare themselves and make sure they are able to follow the strict protective measures. If in doubt, you can always contact your doctor by phone, but always mention before your consultation that you suspect to be infected with the mpox virus.

• Avoid contact with infected people (or people who are suspected to be infected) until they are allowed to leave isolation.

• Limit your sexual contacts and discuss mpox with your partner. Anonymous sexual contacts are a risk and make it difficult to notify exposed partners in time.

There is currently no approved medication that provides complete protection against an exposure. Vaccination is currently a tool to reduce the further spread of mpox. It is offered both immediately after a risk exposure (such as after sex with a patient who tested positive for mpox) and before a risk exposure with certain target groups (see “Who is currently eligible for vaccination?” ).

Due to limited data on individual protection, the vaccine cannot be seen as the ultimate solution against mpox. After vaccination, one can still be susceptible to mpox. A vaccine therefore does not guarantee protection.

• Vaccination is a good tool to prevent mpox, but it does not fully protect. mpox infections after vaccination have been observed.  Exact data on the degree of individual protection after vaccination are not yet available.

General measures remain necessary:

• modification of risk behaviour

• isolation

• avoiding sexual and skin-to-skin contact with sick people

Sometimes a scar remains. A small minority of patients need to be hospitalised, usually for pain control. Serious complications, such as severe inflammation or infection of the skin lesions, occur rarely. Fortunately, the fatality rate of the disease is very low.

Targeted antiviral drugs are currently only used for research purposes. In case of complaints, the symptoms are treated with analgesics, antipyretics, anti-itch medicines, etc. Serious cases with a complicated form of mpox can be treated with the antiviral drug tecovirimat (currently only during hospitalisation). These are usually patients with some form of immune abnormality, such as leukaemia, or patients taking medication that acts on the immune system. A number of treatments are available in Belgium.

Because the mpox virus is closely related to smallpox, the smallpox vaccine is thought to offer good protection against mpox. However, data on the exact level of efficacy is still limited. The vaccine does not replace general precautions, so after vaccination, stay vigilant and limit your sexual contacts.

In Belgium, there are two available vaccines: Imvanex® and Jynneos®, approved respectively by the EMA (European Medicines Agency) and the FDA (Food and Drug Administration, USA) for the indication of mpox. If you are receiving the Jynneos® vaccine, you have to sign a form beforehand, as Jynneos® is only officially approved in the United States.

Other vaccines, such as those against chicken pox (varicella) or zona, do not protect against mpox.

• Stay at home. You should only leave the house for essential reasons, such as medical appointments and urgent errands that no one else can take care of. Wear a surgical mouth mask and cover the skin lesions (by wearing long sleeves and trousers, for example) in case you must leave the house.

• Stay in your own room. Wear a surgical mask if you leave your room and/or have contact with housemates.

• Do not share household items such as clothing, bedding, towels and eating utensils with other household members.

• Avoid physical (sexual) contact until the skin lesions have healed (scabs have fallen off). Condoms alone do not provide full protection against mpox.

• Avoid contact with animals, especially rodents such as mice, rats, hamsters and guinea pigs.

• Notify the people with whom you've had close contact in the last three weeks. This way, you ensure that they can monitor themselves for fever and skin symptoms and act accordingly in case any symptoms appear.

• Extensive medical information - Centers for Disease Control CDC (EN)

• Factsheet - World Health Organization WHO (EN)

• Medical information for the general public - RIVM (NL)

• Information on the evolution of the monkeypox epidemic in Europe (number of cases per country) - ECDC (EN)

• Monkeypox - Agency for Care and Health (NL)

• Monkeypox - Sciensano (NL)

• Green line 1700 (call centre) - Agentschap Zorg Vlaanderen (NL)

We expect that during an active monkeypox infection, high concentrations of the virus are present on all mucous membranes (mouth, anus, urethra) and on the skin for several weeks. Any kind of contact with these mucous membranes (anal, oral, vaginal) and skin can cause transmission. We see that most people contract monkeypox through sexual contact. We recommend not being sexually active (insertive oral, anal, vaginal) for at least 21 days or until all skin lesions have healed. Kissing, tongue kissing and intense nude cuddling are also considered risk contacts.

A monogamous sexual relationship or masturbation do not pose a risk.

Very high-risk contacts include:

• sexual contacts.

• prolonged skin-to-skin contact while the infected person had a skin rash.

High-risk contacts include:

• living in the same household or environment as the infected person.

• sharing clothing, bedding or kitchen utensils while the infected person had a rash.

• caring for an infected person while that person has symptoms.

• contact with an infected person in the course of (para)medical care, without proper personal protective equipment (PPE).

• a sharp injury or exposure (without personal protective equipment) to body fluids of an infected person or to aerosols generated during a (medical) procedure.

• exposure to a contaminated sample during lab procedures, without PPE.

• sitting one or two seats away from a symptomatically infected person for three hours or more, in an airplane, bus or train.

The most common side effects are:

• Discomfort at the place of injection: pain, redness, swelling, hardening and itching. Pain and swelling are more common with subcutaneous injections into the upper arm. With an intradermal injection into the forearm, itching and rashes are more frequent. With the second intradermal injection, this is much more frequent than the first dose, and occurs in almost everyone.

• Headache, muscle pain, nausea, fatigue.

The current smallpox vaccine contains a live, but non-replicating virus and thus falls in the classification between the groups of ‘live-attenuated vaccines’ and ‘inactivated vaccines’. As there is no extensive experience with this intermediate group as of yet, the recommendations for live-attenuated vaccines are maintained.

As a safety precaution, it is recommended to respect an interval of at least 4 weeks with live attenuated vaccines, such as the measles or yellow fever vaccine.

To be on the safe side, it is recommended to respect an interval of at least 2 weeks with the flu vaccination and the COVID-19 vaccination.

Until the end of 2022, persons belonging to a risk group for mpox could be vaccinated preventively. The Flemish government has decided to end the preventive vaccination campaign against mpox as of 2023. This means that as of today it is no longer possible to get a vaccine against mpox. Exceptions are people who have already received a first vaccination against mpox in 2022; they can still get their second vaccination.

If you are still eligible for a second vaccination against mpox, it is best to contact one of the centres below as soon as possible.

• Antwerp: Institute of Tropical Medicine (03 247 66 66)

• Brussels:

  • CHU Sint Pieter (02 535 31 77)

  • VUB (02 477 60 61)

  • UCL (02 764 21 22)

  • ULB (02 555 72 00)

• Hainaut: CHU Charleroi (071 92 22 58, 071 92 23 07)

• Limburg: Jessa Hospital (011 33 81 11, 011 33 76 50)

• Liège: CHU Liège (04 270 31 90)

• Namur: Mont-Godinne CHU (081 42 28 61 on weekdays, 081 42 31 01 in weekends)

• East Flanders: UZ Gent (09 332 21 11, 09 332 23 50)

• West Flanders:

  • Bruges: AZ Sint Jan (050 45 23 12)

  • Ostend (050 45 23 20)

If your file had been prepared by your HIV specialist, ITM will only charge for a medical consultation. Should you need a doctor's opinion during your visit, you will be charged according to the applicable RIZIV nomenclature.

Even if you have had monkeypox in the past, you should always avoid exposure to the virus. After a monkey pox infection, the general preventive guidelines still apply.