What further dynamics of spread of monkeypox can be expected? How effective will preventive and control measures against the infection be? According to German experts, these and other questions cannot yet be answered. There is a lack of data.

If an outbreak in Nigeria that had been going on for years – and thus unusually long – had been examined more closely, this data could have existed, at least in part, long ago. Chikwe Ihekweazu, the former director-general of the Nigerian Center for Disease Control, told Stat News. His country had asked for international support with limited success. Today, Ihekweazu heads the World Health Organization (WHO) epidemic early warning center in Berlin.

After decades of no cases in Nigeria, an outbreak began in 2017. This continues to this day. The virus has been brought from Nigeria to other countries on several occasions when infected people traveled to the USA, the UK, Israel and Singapore.

More and more cases are being reported in 14 European countries, Australia, the United States, Canada, Israel, among others. Twelve cases and one suspected case are known in Germany. According to the Robert Koch Institute, what is special about these cases is that those affected had not previously traveled to African countries where the virus occurs. The virus may have acquired properties that make human-to-human transmission more likely.

Nevertheless, the stronger support for infection control in Nigeria could have provided German authorities with more data that would now be helpful in assessing the infection process and its containment. These include a more accurate assessment of mortality, the protective effect of smallpox vaccination and the reproductive value “R” in a largely unimmunized population.

However, Gérard Krause, epidemiologist at the Helmholtz Center for Infection Research in Braunschweig, assumes that the dynamics of the infection process outside of Africa are different. In Nigeria, sick people often come into contact with animals that can transmit the virus. Human-to-human transmissions were observed there in isolated cases and only in one prison. “The mortality rate was also significantly higher during the outbreak in Africa,” Krause told the Science Media Center Germany. He suspects that it will remain significantly lower in the current cases outside of Africa, as the sick receive better medical care.

“We examined numerous samples from the outbreaks in Africa,” says Roman Wölfel, senior physician and head of the Bundeswehr Institute for Microbiology in Munich. However, it is difficult to draw any conclusions about the importance of genetic changes if only the situation in Africa is used for comparison.

The monkeypox virus genome consists of DNA and is therefore considered to be more stable than the genome of RNA viruses. “We tend not to see the formation of variants that we see in the Sars-Cov-2 coronavirus in smallpox viruses and the monkeypox virus,” says Wölfel.

The examination of the genome of the virus with which the first patient in Germany is infected – and now also the other patients – is not yet complete. Selective changes in the genetic information are rarer, but could change the properties of the virus, for example if genes are blocked or blockages are removed. “So far, however, we have not seen any groundbreaking changes in the genome in the studies in other countries either,” says Wölfel.