Drugs and vaccines against the virus at a glance

Another virus is causing international unrest. This time it’s the monkeypox virus. So far, the pathogen has mainly spread in West and Central Africa, but now it is appearing in several countries around the world at the same time. Belgium, France, Italy, Portugal, Spain, Sweden, Great Britain, Canada, the USA, Australia – they all report infections with the virus. The first cases are also known in Germany.

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Monkeypox infections usually present with symptoms such as fever, headache, muscle and back pain, and swollen lymph nodes. Also typical are skin lesions that begin on the face, hands, and forearms and then spread over the body. This initially creates spots on the skin, which develop into nodules and then into purulent blisters.

The symptoms usually disappear after several weeks. However, serious illnesses are also possible, especially in young and immunocompromised people. What is the best way to protect yourself from monkeypox? What vaccines and medications are there for the disease? And how well does a previous smallpox vaccination protect against the monkeypox virus? Here come the answers:

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I got infected with the monkeypox virus and have symptoms. What has to be done now?

Symptoms that indicate an infection with the monkeypox virus should be clarified by a doctor. The most noticeable are skin changes, which can look like this:

Image provided by the UK Health Security Agency (UKHSA) shows skin lesions in patients diagnosed with monkeypox.

Since the authorities recently assumed that there was a sexual chain of infection from men who had same-sex sex, the Robert Koch Institute (RKI) advises this group to “seek immediate medical care” in the event of skin changes. If infected with the monkeypox virus, close physical contact with others should be avoided and hygiene should be observed.

How does the smallpox vaccine protect against monkeypox?

In 1980, the World Health Organization (WHO) declared the causative agent of smallpox, the variola virus, to be eradicated worldwide. The massive vaccination campaign that had made this possible was then discontinued. Immune protection in the population has decreased significantly since then: British researchers wrote in a Study published in July 2020 in the journal “Vaccine”.that an estimated 70 percent of the world’s population is no longer protected against smallpox.

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The dwindling population immunity to the variola virus could play a role in the current monkeypox outbreak, tweeted Leif Erik Sander, Head of the Clinic for Infectious Diseases at the Berlin Charité. The variola virus and the monkeypox virus are closely related. An earlier smallpox vaccination therefore protects against both pathogens. Several observational studies have found that smallpox vaccination is about 85 percent effective in preventing monkeypox, the agency writes WHO.

If declining immunity is indeed contributing to the development of monkeypox, booster vaccinations could help to curb the spread of the virus. So-called ring vaccinations are already taking place in Great Britain. This means that the contact persons of all those infected with monkeypox are offered a vaccination. There is one problem with this, however – and that is the vaccine.

What vaccines can be used against monkeypox?

Early smallpox vaccinations used live vaccines containing reproducible smallpox viruses. Skin lesions, the characteristic scars of the smallpox vaccination, therefore usually formed at the puncture site. These vaccines are no longer available. Likewise, there is no vaccine specifically approved against monkeypox.

The only vaccine approved against smallpox in the EU is Imvanex. A live vaccine that contains a genetically modified smallpox virus, Modified Vaccinia Virus Ankara (MVA). The vaccine virus is modified in such a way that it can neither trigger the disease nor multiply in the human body. According to Danish manufacturer Bavarian Nordic A/S, the vaccine is only approved in Europe to immunize adults against smallpox, “but was previously made available for off-label use in cases of monkeypox.”

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In Canada and the USA, the vaccine can be used against both smallpox and monkeypox. For effective vaccination protection, two doses of 0.5 milliliters are required at an interval of 28 days Website of the European Medicines Agency Ema. Anyone who has already received a smallpox vaccination only needs one dose – with the exception of people with a weakened immune system.

Clinical studies would suggest that Imvanex produces high antibody responses that are expected to protect against smallpox, Ema said. However, it is not yet known how long this protection will last. And the protective effect against monkeypox is still unclear.

Die European disease control agency ECDC advises in any case: “If smallpox vaccines are available in a country, after a risk-benefit assessment, vaccination of close risk contacts should be considered.” However, availability is a challenge. The WHO describes Imvanex as a smallpox vaccine “which is only available in limited quantities”.

Are there any medications for monkeypox?

Similar availability problems exist with anti-monkeypox drugs. The RKI only lists the drug Tecovirimat as a possible therapy option – especially for immunocompromised people who contract the monkeypox virus. It has been approved in the EU since January 2022.

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The drug is recommended by the Ema for adults and children with a body weight of at least 13 kilograms. These are capsules that are only available with a doctor’s prescription. Tecovirimat attacks a protein called VP37, which is found on the surface of smallpox and monkeypox, preventing the virus from multiplying in the body. It slows down the spread of the infection.

How well Tecovirimat works in people infected with smallpox is still unclear. The Ema writes: “Because smallpox, monkeypox and cowpox have either been eradicated in the EU (pox) or occur sporadically, no studies could be carried out to evaluate the effectiveness of Tecovirimat SIGA in infected people.” Even if the drug was used in those infected with monkeypox proves effective, it is not yet widely available.

So the only thing left for the doctors to do at the moment is to treat the typical symptoms of monkeypox with medication. The skin lesions in particular must be treated accurately. If bacteria get into the wound, the worst that can happen is bacterial superinfection.

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