A few cases of monkeypox have been reported in Europe. One expert assumes that vaccination against monkeypox will always be a case-by-case decision.

More and more cases of the viral disease monkeypox are being diagnosed internationally. According to the Robert Koch Institute, ten cases have been confirmed in Germany (as of May 25, 2022). Experts assess the risk of a major outbreak as low. But many questions still have to be answered in research. What is already known and what is important now.

How can I tell if I’ve contracted monkeypox?

The first symptoms, such as fever and headaches, are still very unspecific, says Professor Clemens Wendtner in a press briefing by the Science Media Center. He is chief physician for infectiology and tropical medicine and head of the special unit for highly contagious life-threatening infections at the Schwabing Clinic in Munich. He treats the first monkeypox case that was detected in Germany. “Anyone who notices skin changes on themselves – especially after close physical contact and unprotected sex with different partners – should have these skin changes clarified by a doctor.” Dermatologists are one point of contact. The Robert Koch Institute emphasizes: “The risk of contracting monkeypox is not limited to sexually active people or men who have sex with men.” The overall risk from the disease is estimated by health authorities to be moderate for people with multiple sexual partners and low for the broader population.

Are there any new insights into transmission?

In Munich, the monkeypox virus was successfully detected in semen. “Ultimately, we are also dealing with a sexually transmitted disease,” says Clemens Wendtner. “But it is not so easy to say that transmission via the sperm is possible. Because: Transmission already occurs through close physical contact,” says Professor Roman Wölfel, classifying the find. He is a senior physician and head of the Bundeswehr Institute for Microbiology. He sequenced the first monkeypox genome in Germany. “Even if the virus occurs in a large number of body fluids, it also occurs in the typical smallpox pustules. These are definitely infectious. In fact, sexuality not only has something to do with the transmission of seminal fluid, but is in most cases involving close physical contact,” he continues. This means that in most cases the virus is transmitted through close physical contact.

Will it be necessary for the population to be vaccinated?

Gérard Krause, head of the epidemiology department at the Helmholtz Center for Infection Research, does not expect vaccination against monkeypox for the general public. “As far as is currently foreseeable, the vaccination will only ever be an individual decision. This is certainly not something that is generally recommended by the Stiko and then offered on a broad basis.” Vaccination against monkeypox will be a focused tool for specific situations in a limited, well-defined population, Krause said.

What is the difference between the current monkeypox outbreak and that in Nigeria in 2017/2018?

The dynamics of the outbreak in Nigeria were different, says Gérard Krause. He provided epidemiological support for the outbreak in Nigeria. During the outbreak in Nigeria, there were only isolated cases of human-to-human transmission. “Many of the infections could be traced back to animal exposure.” Means: People have contact with infected animals. “The current outbreak is probably only to a very small extent due to animal exposure and is largely transmitted from person to person,” says the expert. Due to better medical care, a different situation of previous illnesses and hygiene, the mortality rate is very likely lower than in Africa. Both outbreaks have cases that have occurred geographically far apart.

How fast could monkeypox spread?

Estimates of the current outbreak are not yet available because there is not enough data, explains Professor Mirjam Kretzschmar, expert in mathematical disease modeling at the Julius Center for Health Sciences and Primary Care at the University Medical Center Utrecht. “We know estimates from Africa from the last few decades, when the R value was always below 1. There were only small and short-term outbreaks.” The R value describes how many people an infected person infects on average. “The smallpox vaccination is also partially effective against monkeypox. In the last few decades, a large part of the population was vaccinated against smallpox, but the proportion is becoming smaller and smaller. As a result, the immune protection in the population may decrease. The R value could therefore be higher because fewer people in the population are protected,” says the expert. To what extent this is the case is not yet known. The majority of people over the age of 50 should still have basic immunity, says Mirjam Kretzschmar.

Could the monkeypox virus change greatly like we have seen in the corona pandemic?

Monkeypox are so-called DNA viruses. In contrast to RNA viruses such as Sars-CoV-2, the genome of these viruses is quite stable. This means that mutations occur less frequently, explains Roman Wölfel.

What needs to be done in the next steps?

The four experts agree that good contact tracing and further microbiological investigations are important to better understand the current outbreak.

Sources: SMC press briefing, with DPA material