The CDC said the clade IIb mpox virus is likely to become endemic in the U.S. in an Aug. 20 Morbidity and Mortality Weekly Report.
“Persistent transmission of [mpox] in the United States, with wide geographic spread during the last 3 years, suggests a transition toward endemic circulation,” the Aug. 20 CDC report said.
Here is what to know.
1. Since the global outbreak of mpox virus in 2022, the U.S. has seen cases significantly decline; however, ongoing low-level transmission remains persistent.
2. In 2024, a total of 2,803 cases of mpox infection were reported, compared to 2,519 cases in 2025. Between September and October 2025, the reported cases of mpox doubled compared with the same period in 2024.
3. Unvaccinated patients account for 76.1% of cases and have 9.7 times the odds of hospitalization as those who completed the 2-dose Jynneos vaccination series.
4. Cases continue to disproportionately affect men who have sex with men.
