Mpox cases are far outpacing last year's numbers, CDC reports

More than 570 cases of mpox have been detected in the U.S. so far in 2024 — nearly double the number seen by this time last year.

This infection rate doesn't come close to that seen at the peak of the mpox outbreak in early August 2022, when the U.S. saw an average of about 470 new cases in a week. However, the new data highlight that mpox is still circulating and that there's still a need for people who are at risk of infection to get vaccinated.

The most widely used mpox vaccine in the U.S., called JYNNEOS, is given in two doses spaced a month apart. A person is fully vaccinated two weeks after their second dose, and no booster shots are currently recommended. You can check whether you're eligible for the vaccine and where to get the shots on the Centers for Disease Control and Prevention (CDC) website. Various local Health departments, such as those of New York City and San Francisco, also have their own vaccine-site finders.

The vaccine is not widely recommended to everyone. Rather, select groups — for example, gay and bisexual men with recent sexually transmitted infection (STI) diagnoses — have been identified as at risk of mpox and made eligible for the shots.

Related: Should everyone get a monkeypox vaccine?

"Most of the cases that we're seeing reported are either unvaccinated or under-vaccinated, meaning they either never received a vaccine, or they only got one dose," Dr. Jenni McQuiston, deputy director of the CDC's High-Consequence Pathogens and Pathology division, told ABC News.

Mpox, formerly known as monkeypox, is caused by a relative of the now-eradicated variola virus, which causes smallpox. Mpox viruses come in two broad types: clade I and clade II. Clade I is more likely than clade II to cause severe and fatal disease. Although clade I has not been detected in the U.S. to date, it's possible that Travelers could carry the viruses to the country from other places, such as the Democratic Republic of the Congo, the CDC cautioned in December 2023. The JYNNEOS vaccine guards against both clades.