Emergent BioSolutions announced on Monday that it would donate 50,000 doses of its smallpox vaccine to the Democratic Republic of the Congo and other affected countries, including Burundi, Kenya, Rwanda, and Uganda, to help combat the ongoing mpox outbreak.
Last week, the World Health Organization declared mpox a global public health emergency for the second time in two years, as a new variant of the virus, clade Ib, rapidly spread across Africa. This variant was recently detected outside of Africa for the first time, with at least one confirmed case in Sweden.
Emergent’s ACAM2000 vaccine, originally approved for smallpox, has been used to combat mpox, though the U.S. Food and Drug Administration has yet to approve it specifically for this purpose. According to the U.S. Centers for Disease Control and Prevention, ACAM2000, a live, replicating virus vaccine, has more known side effects and risks than the Jynneos vaccine from Danish biotech Bavarian Nordic A/S, which is approved in the U.S. for both smallpox and mpox.
One significant risk of ACAM2000 is myocarditis or pericarditis—inflammation in or around the heart muscle—which occurs in 1 in 175 recipients, according to the FDA. Instead of a standard injection, the vaccine is administered through a series of small pricks on the skin using a two-pronged needle.
The injection site forms a scab that takes 2-4 weeks to heal, and until it falls off, the scab can spread the live virus to other parts of the body or to other people. ACAM2000 is not recommended for individuals with compromised immune systems, such as those with HIV.
