Today a Public Health Alerts report describes postexposure prophylaxis (prevention) after 13 people in Wyoming were exposed to anthrax either through inhalation or skin (cutaneous) contact. Postexposure prophylaxis (PEP) involved both antibiotics when appropriate and, for some inhalation exposure, vaccination with a two-dose vaccine.
The exposures occurred after an anthrax outbreak among cattle in 2024 in Wyoming.
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4 people declined vaccination
The Wyoming Department of Health received notice of the 13 exposures in August 2024. Three people had cutaneous exposure only, seven had inhalation exposure only, and three had both exposures. “Cutaneous exposure was defined as direct contact between skin and blood from an infected animal,” the authors note.
All 10 people with inhalation exposure and one of the three with cutaneous-only exposure were within the anthrax incubation period for symptoms to develop (17 days for cutaneous exposure and 60 days for inhalation exposure). Officials recommended that these 11 receive PEP according to Centers for Disease Control and Prevention guidelines. All 11 received preventive doses of doxycycline (PEPabx).
The two-dose anthrax vaccine Cyfendus, made by Emergent BioSolutions, was administered to six of the people exposed, four within the age range (18 to 65 years) approved by the Food and Drug Administration (FDA) and two older adults under emergency use authorization. Four declined vaccination, two within the FDA-approved age range and two children younger than 18.
Rapid initiation and completion of PEP, either as PEPabx or with vaccine, might have helped prevent human infection.
Those who declined the vaccine reported doing so because of general hesitancy, side effect concerns, and a lack of safety data for emergency-use groups.
None of the 13 exposed people tested positive for Bacillus anthracis, the bacterium that causes anthrax.
The authors conclude, “Rapid initiation and completion of PEP, either as PEPabx or with vaccine, might have helped prevent human infections.”
