Mpox Infections after Vaccination
Cases of mpox have been reported 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 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.
What We Are Doing to Find Out

- We are conducting studies to determine how long immunity after vaccination lasts.
- We are looking at specimen samples from these patients to see if the virus has changed.
- We are working closely with our local and state partners to find out:
- How the virus spread among these patients.
- How many patients were vaccinated, if they were fully vaccinated, and when they were vaccinated.
- We are closely monitoring reports of people newly diagnosed with mpox after vaccination.
What Can You Do?
If mpox is in an area where you live or are traveling to:
- Make sure you are up to date on mpox vaccination. Get both doses of the vaccine. It’s never too late to get the second dose.
- Seek health care and get tested if you suspect you have a rash even if you have been previously vaccinated or had mpox.
- Pay attention to public health and community leaders for advice on how to prevent mpox exposure, including potentially changing some parts of your sex life temporarily. Recommendations may include:
- Short-term changes to your sex life to help limit the spread.
- Limiting new or multiple sex partners
- Avoiding sex in places that might be associated with mpox transmission