Philip L F Johnson, Carl T Bergstrom, Roland R Regoes, Ira M Longini, M Elizabeth Halloran, Rustom Antia
The Lancet
September 21, 2022
ABSTRACT
Since May, 2022, clusters of monkeypox infections have caused global concern. At present, this concern has been tempered by the fact that, even when uncontrolled, the number of infections is growing slowly, indicating a reproductive number (R) not much larger than unity. However, the effect of R on the probability of evolution might not be obvious. We suggest that, compared with zoonotic pathogens with large R values, those pathogens with R values just above 1, such as monkeypox virus, have a higher probability of evolution during the timeframe in which the number of cases remains low. Waiting until the number of cases is high would give monkeypox virus—or any emerging pathogen—the opportunity to adapt substantially to humans.