CDC Health Update: Potential Risk for New Mpox Cases

The Centers for Disease Control and Prevention (CDC) released a Health Advisory Network (HAN) Health Update to raise awareness that although cases of mpox (formerly monkeypox) have declined, the CDC continues to receive reports of cases that reflect ongoing community transmission in the United States and internationally. The CDC is currently investigating a cluster of 12 confirmed and 1 unconfirmed mpox cases in the Chicago area. There is concern that a resurgence in cases may occur as the weather becomes nicer and people gather at festivals and other events.

Although vaccine-induced immunity is not complete, vaccination continues to be one of the most important prevention measures. CDC expects new cases among previously vaccinated people to occur, but people who have completed their two-dose JYNNEOS vaccine series may experience less severe symptoms than those who have not.

Recommendations for Healthcare Providers

• Be on alert for new cases of mpox and to encourage vaccination for people at risk.
• If mpox is suspected, test even if the patient was previously vaccinated or had mpox.
• Notify state or local health departments of any suspected or confirmed mpox cases (via 24-hour Epi On Call contact list).
• Clinicians should refamiliarize themselves with mpox symptoms, specimen collection, laboratory testing procedures, and treatment options.
• Tecovirimat (TPOXX) and JYNNEOS vaccine continue to be available through the National Supply Service Center (NSSC) via the Mpox Therapeutics Request Form

Vaccination

• CDC does not recommend routine immunization against mpox for the general public.
• Mpox vaccination should be offered to people with high potential for exposure to mpox.
• JYNNEOS involves 2 vaccine doses given 28 days apart; peak immunity is expected 14 days after the second dose.
• People who are vaccinated should continue to avoid close, skin-to-skin contact with someone who has mpox.

Treatment

• Patients with mpox benefit from supportive care and pain control.
• Tecovirimat is available upon request for mpox patients who meet treatment eligibility (e.g., have severe disease or are at increased risk for severe disease) under CDC’s Expanded Access Investigational New Drug (IND) protocol.
• JYNNEOS vaccine can be given as post-exposure prophylaxis (PEP) both to people with known or presumed exposure to the mpox virus.
• JYNNEOS vaccine can be given to people with certain risk factors and recent experiences that may make them more likely to have been exposed to mpox.
• As PEP, vaccine should be given as soon as possible, ideally within 4 days of exposure; however, administration 4 to 14 days after exposure may still provide some protection against mpox.

More information about evaluating and treating patients can be found on the CDC mpox Clinical Guidance web pages.