Mpox Vaccine Wanes Quickly, Are Boosters Needed

According to a research letter published in the Journal of the American Medical Association (JAMA), Bavarian Nordic’s mpox vaccine JYNNEOS® (MVA-BN®) protection appears to weaken within six to 12 months after injection.

Two doses provided 66% effectiveness, and one dose provided 36% effectiveness at peak immunity during the 2022 clade 2 mpox outbreak.

This finding raises questions about whether the two-dose vaccine may been 'booster' shots to confer lasting protection against the mpox virus.

However, the U.S. CDC wrote on September 12, 2024, 'Right now, getting more than two mpox vaccine doses (a "booster") isn't recommended.'

“Our data suggest that protective immunity may be waning in individuals who were vaccinated with this vaccine in 2022,” corresponding author Dan Barouch said in a related statement on October 3, 2024.

On September 26, 2024, Bavarian Nordic announced an agreement with UNICEF to supply 1 million doses of the MVA-BN® mpox / smallpox vaccine for African countries confronting the clade 1 mpox outbreak.

In the United States, JYNNEOS is now commercially available at clinics and pharmacies.