evidence: Wealthy countries with millions of smallpox vaccines stockpiled for national security should urgently donate more doses to African countries battling the latest outbreak of mpox, the World Health Organization has warned. [...] Many of these smallpox vaccines are also effective against mpox as the two viruses are closely related. Yet, as a worrying outbreak of a dangerous new mpox strain intensifies in east Africa, few vaccines have reached the hardest hit regions. [...] That has now jumped, after the United States on Tuesday pledged a donation of 1 million mpox vaccine doses and at least $500 million to African countries to support their response to the outbreak.