CDC: The Virus Continues to Spread... 　

Emergency Message System

May 17th, 2023

Mpox Infections after Vaccination

A cluster of mpox cases have been reported in the Chicago area, which means the virus is still spreading, and we need to continue to be alert. More than 50% of cases in the cluster have been in people who have been previously vaccinated. Getting vaccinated is still very important. No vaccine is 100% effective, and infections after vaccination are possible, but they may be milder and less likely to result in hospitalization.

What We Know

Vaccination makes getting and spreading mpox less likely.
Infections after any vaccination are possible. No vaccine is 100% effective.
If you have a rash or other symptoms of mpox, you should get tested even if you have been vaccinated or had mpox.
Getting vaccinated against mpox may help make the symptoms less severe and easier to manage.
The vaccine may help protect you against severe infection, hospitalization, and death.
CDC recommends getting vaccination for those who are at risk.

What We Don't Know

We don’t know why people in this cluster of cases have gotten mpox after vaccination.
We don’t know if immunity after vaccination has decreased in these cases or how long the vaccine protects against mpox infection.
We don’t know if the virus has changed.