Smallpox Antiviral May Help Ease Monkeypox Symptoms
The study analyzed all seven patients diagnosed with monkeypox in the U.K. between August 2018 and September 2021, and was conducted by researchers from Liverpool University Hospitals NHS Foundation Trust, Liverpool School of Tropical Medicine and other institutions.

The only patient who took the smallpox antiviral tecovirimat spent only 10 days in the hospital with monkeypox, about 15 days less than average for the series of patients as a whole, the study found. However, the study’s authors said they could not draw hard-and-fast conclusions because of their small sample size, and recommended further research into tecovirimat and other possible smallpox treatments.

The U.S. keeps 1.7 million doses of tecovirimat in its Strategic National Stockpile, pharmaceutical manufacturer SIGA Technologies announced in 2021, which could be a major asset for monkeypox response if the drug’s effectiveness is confirmed by additional research.

Three patients included in the study took brincidofovir, a smallpox antiviral that—like tecovirimat—has proven effective against monkeypox in animals, but brincidofovir did not show any effectiveness against monkeypox among those patients, and was consistently associated with impaired liver function.