by Adolf Albus
(09.01.2023) Cell culture studies by Goethe University and the University of Kent prove the effectiveness of tecovirimat, cidofovir and brincidofovir – Frankfurt working group is funded by the Frankfurt Foundation for Children with Cancer.
The monkeypox virus is closely related to the smallpox virus (variola virus), which caused large outbreaks with high death rates until it was eradicated by vaccination in the late 1970s. While smallpox, now eradicated, caused a very severe disease with a mortality rate of about 30 percent, monkeypox is a milder disease. Despite this, the death rate is still around three percent. People with a weakened immune system, the elderly, pregnant women, newborns and small children are particularly at risk from a severe course. Until recently, monkeypox was only found in certain parts of Africa when humans contracted it through contact with wild animals, primarily rodents such as the Gambian hamster rat or the red-shanked squirrel.
However, in May 2022, for the first time, a large monkeypox outbreak was detected outside of Africa; the viruses spread solely through human-to-human transmission. This ongoing outbreak has so far reached more than 100 countries and has been classified by the World Health Organization as a Public Health Emergency of International Concern.
About 10 percent of monkeypox patients require hospital treatment. In addition, the current monkeypox outbreak differs from previous outbreaks not only in its transmission path, but also in the symptoms of the disease. These differences in virus behavior raised concerns that the currently circulating monkeypox viruses had changed to the point where they were no longer responsive to available drugs.
In this context, an international research team led by Prof. Jindrich Cinatl from the Institute for Medical Virology, Goethe University Frankfurt/University Hospital Frankfurt, and Prof. Martin Michaelis from the School of Biosciences at the University of Kent, succeeded in detecting monkeypox viruses from 12 patients of the current outbreak and propagate them in cell culture. This allowed these monkeypoxvirus isolates to be tested in cultures of skin cells naturally infected by monkeypoxvirus for their susceptibility to three available drugs used to treat monkeypox: tecovirimate, cidofovir and brincidofovir.
Results showed that all 12 isolates continued to respond to treatment with clinically achievable concentrations of commonly used drugs.
Prof Jindrich Cinatl said: “We were really concerned that the virus might have evolved in a way that made it resistant to current therapies. Fortunately, this is not the case.”
Prof. Martin Michaelis added: “These results are very reassuring and give reason to believe that the available antiviral therapies will continue to be effective against monkeypox in the current outbreak.”
The Frankfurt research group “Interdisciplinary Laboratory for Pediatric Tumor and Virus Research” headed by Prof. Jindrich Cinatl is funded by the Frankfurt Foundation for Children with Cancer and is in the Dr. Petra Joh Research House of the foundation.
Publication: Denisa Bojkova, Marco Bechtel, Tamara Rothenburger, Katja Steinhorst, Nadja Zöller, Stefan Kippenberger, Julia Schneider, Victor M. Corman, Hannah Uri, Mark N. Wass, Gaby Knecht, Pavel Khaykin, Timo Wolf, Sandra Ciesek, Holger F Rabenau, Martin Michaelis, Jindrich Cinatl jr. Drug sensitivity of currently circulating monkeypox viruses. New England Journal of Medicine (2022) https://www.nejm.org/doi/full/10.1056/NEJMc2212136