Last week, the World Health Organisation declared mpox a global public health emergency for the second time in two years due to the rapid spread of a new variant, clade Ib, across Africa.
This variant has now reached Sweden, marking its first appearance outside the continent.
Emergent’s ACAM2000 vaccine, initially approved for smallpox, has been repurposed to address mpox, though it has not yet received specific approval from the FDA for this use.
The Centers for Disease Control and Prevention (CDC) reports that ACAM2000, a live virus vaccine, has more recognised risks and side effects compared to Bavarian Nordic’s Jynneos vaccine, which is FDA-approved for both smallpox and mpox.
ACAM2000 is associated with myocarditis or pericarditis, which is inflammation of the heart or its lining, in about 1 in 175 recipients, according to the FDA.
Unlike traditional injections, ACAM2000 is administered through a series of small punctures on the skin with a two-pronged needle.
This method creates a scab at the injection site, which can take 2 to 4 weeks to heal and may spread the live virus during that period.
The vaccine is not recommended for individuals with weakened immune systems, such as those with HIV.