CDC: Studies reinforce effectiveness of mpox vaccination for people at risk

As summer Pride parades and other large gatherings approach, Americans at high risk for mpox (monkeypox) exposure should ensure they are fully vaccinated with the JYNNEOS vaccine as recommended, the Centers for Disease Control and Prevention advised, pointing to three new studies supporting the vaccine’s effectiveness against the virus.

A study using nationwide electronic health record data published today in the New England Journal of Medicine found a two-dose series of the vaccine was 66% effective at preventing medically attended mpox disease among adults, while two smaller studies found two doses were 86% and 88% effective, respectively.

The CDC continues to investigate an mpox outbreak in the Chicago area, where most of the 21 men infected to date had received at least one dose of vaccine. All of the patients had mild symptoms, officials said. For more information and the latest recommendations for clinicians, see this week’s CDC advisory.