Study: Delayed Intervention Makes Eliminating Monkeypox More Difficult

Vaccinations and lifestyle adjustments in at risk-populations have enabled public health authorities to gradually get a better handle on monkeypox in the U.S., but new University of Maryland research warns that it’s too soon to relax.

Waiting for another surge in cases to act gives time for stronger and more dangerous variants to evolve, according to the study published late Wednesday in the medical journal The Lancet.

“Just because a disease like monkeypox appears controllable does not mean it will stay controllable,” said the paper’s lead author, biology Assistant Professor Philip Johnson. “Slowly simmering epidemics like monkeypox have a higher probability of evolution during the time frame while case numbers are low.”

Just over 24,000 cases of the disease have been diagnosed in the United States, including 625 in Maryland, according to the latest data from the U.S. Centers for Disease Control.

In the paper, Johnson and his co-authors analyzed other high-profile outbreaks exacerbated by pathogen evolution, including the 2013-16 Ebola virus outbreak and the delta and omicron variants of SARS-CoV-2. These evolutionary changes likely made the viruses more difficult to control.

“We expect zoonotic infections—diseases that originate from animals, like Ebola from bats and monkeypox from rodents—to be poorly adapted to people when they first jump between species,” Johnson said. “But given enough time, the pathogens can mutate just a little with each new transmission and become increasingly better at thriving in humans.”

The team, which includes co-authors hail from the University of Washington, Seattle, University of Florida, Gainesville, Fred Hutchinson Cancer Center and Emory University, hopes the research will encourage policymakers to avoid complacency and procrastination when tackling seemingly “controllable” viruses like monkeypox. If implemented quickly and consistently enough throughout an epidemic’s lifecycle, control measures like contact tracing or vaccination may give public health authorities the best chance to fully eradicate the outbreak before significant evolution occurs.

In the long term, the team’s goal is to increase global responses to emerging zoonotic diseases when they’re relatively cheaper and easier to control.

“Pathogen evolution can’t be stopped, but it can definitely be slowed by control measures,” Johnson said. “We have finite public health resources, meaning that we need more research to develop tools that can identify possible early-stage evolutionary adaptations and help guide control efforts to where they’ll be most effective."