CDC Studies Support Mpox Vaccine as Safe and Effective

Media Statement

For Immediate Release: Friday, December 9, 2022
Contact: Media Relations
(404) 639-3286

Studies show vaccinated people have substantially less risk for contracting mpox compared with those who are unvaccinated and identified no major safety concerns after nearly 1 million doses administered.

New data released today in CDC’s MMWR provide additional evidence to support that vaccination with the JYNNEOS mpox vaccine is safe and reduces the risk for getting mpox. CDC recommends vaccination for people at risk for getting mpox.

The first report looked at vaccine safety data among children and adults and found no major vaccine safety concerns after nearly 1 million JYNNEOS doses were administered. Common adverse health events reported were consistent with studies before the vaccine was licensed, including injection site redness, swelling, or pain, and dizziness.

The second report found rates of mpox illness in unvaccinated people were 10 times higher compared to those who had received both doses of the JYNNEOS vaccine, and there was no difference between intradermal and subcutaneous routes of administration. These findings provide additional evidence supporting the protective effect of vaccination.

“Mpox cases are decreasing, but so is public concern,” said Jonathan Mermin, M.D., M.P.H., mpox response Incident Manager. “With a safe, effective vaccine in our hands, this is our chance to turn the page and finish strong.”

CDC encourages everyone who is eligible for mpox vaccination to receive the complete two-dose series for best protection.


CDC works 24/7 protecting America’s health, safety and security. Whether diseases start at home or abroad, are curable or preventable, chronic or acute, or from human activity or deliberate attack, CDC responds to America’s most pressing health threats. CDC is headquartered in Atlanta and has experts located throughout the United States and the world.