MPOX TRACKER

The UK Health Security Agency (HSA) has reclassified clade 1a and 1b mpox, determining they no longer meet the threshold for a high-consequence infectious disease. This decision follows a review by the Advisory Committee on Dangerous Pathogens, which cited evidence of low mortality rates and the availability of vaccines and treatments. The HSA emphasized, however, that mpox remains a public health concern, particularly for travelers to affected regions in Africa.

Emma Richards, HSA’s incident director, stated that while mpox can cause severe symptoms—including unusual blisters, fever, and headaches—vaccination, improved diagnostics, and heightened clinical awareness have significantly reduced its threat level. The agency urges vigilance among those who have traveled to high-risk areas, as close physical contact remains the primary mode of transmission.

In related developments, the U.S. National Institutes of Health (NIH) has confirmed that tecovirimat (Tpoxx), initially developed for smallpox and hoped to be effective against mpox, has failed to demonstrate clinical benefits for clade 2 infections. The international trial, which began in 2022 and included a study in the Democratic Republic of the Congo, found that Tpoxx did not reduce recovery time or alleviate pain. The findings were presented at the 2025 Conference on Retroviruses and Opportunistic Infections (CROI).

Despite the reclassification of mpox in the UK, continued research into more effective treatments is critical, particularly given the persistent spread of clade 1b in Africa. The NIH trial highlights the need for alternative antiviral therapies, and global health authorities must remain proactive in monitoring emerging mpox variants to prevent further outbreaks.