On Feb. 14, 2023, scientists from the National Institute of Allergy and Infectious Diseases announced they had developed a mouse model of the disease and used it to demonstrate clear differences in virulence among the major genetic groups (clades) of mpox virus (MPXV). The research, appeared in Proceedings of the National Academy of Science.

Historically, mpox, a disease resembling smallpox, was only occasionally transmitted from rodents to non-human primates or people and was observed primarily in several African countries. Mpox rarely spread from person to person. That pattern changed in 2022 with an outbreak in which person-to-person mpox transmission occurred in more than 100 locations worldwide. To date, more than 80,000 cases of mpox have been diagnosed.