Healthline: What we know about breakthrough monkeypox cases
UC expert says people with certain medical conditions may be less likely to be protected
The World Health Organization announced recently that breakthrough infections have been reported in people who had been vaccinated against monkeypox. Healthline reported there is limited data available on the efficacy of the JYNNEOS shot, so it will take time to understand how effective it is at preventing infection. Data from the 1980s has shown that the vaccine was at least 85% effective, however, some health experts expect that number to change in the current outbreak. One of the experts cited in the Healthline story was Carl Fichtenbaum, MD, of the Division of Infectious Diseases at the UC College of Medicine.
Carl Fichtenbaum, MD, of the Division of Infectious Diseases at the UC College of Medicine/Photo/Joe Fuqua II/UC Marketing + Brand
Fichtenbaum says that the vaccine has not been tested in humans to a large extent, so 85% is really a ballpark estimate.
Healthline reported the strength of people’s immune systems varies and certain individuals may not mount a strong enough immune response to avoid getting sick even if they are fully immunized.
“As always, those with immunosuppression, cancer, transplant patients, and persons with HIV who have a lower CD4+ lymphocyte count below 350 cells/mm3 would be more likely to not respond as well to vaccine and have a breakthrough infection,” Fichtenbaum said.
People older than 60 are also likely to be less protected, Fichtenbaum added.
Fichtenbaum says we are still learning about how common breakthrough infections are, and we don’t have the best track record for preventing the spread of infectious diseases during public health emergencies.
“Time will tell how many breakthroughs occur,” Fichtenbaum said.
Next Lives Here
The University of Cincinnati is classified as a Research 1 institution by the Carnegie Commission and is ranked in the National Science Foundation's Top-35 public research universities. UC's graduate students and faculty investigate problems and innovate solutions with real-world impact. Next Lives Here.
Related Stories
Make Hoxworth Blood Center’s special holiday events part of your family celebrations this December
December 12, 2025
This December, Hoxworth Blood Center, University of Cincinnati, is inviting families across Greater Cincinnati to add something truly meaningful to their holiday traditions: giving the gift of life. With festive community events, beloved local partners and special thank-you gifts for donors, Hoxworth is making it easier, and more heartwarming than ever, to roll up your sleeves and help save lives close to home.
Ohio nurses weigh in on proposed federal loan rule
December 12, 2025
Spectrum News journalist Javari Burnett spoke with UC Dean Alicia Ribar and UC nursing students Megan Romero and Nevaeh Haskins about proposed new federal student loan rules. Romero and Haskins, both seniors, were filmed in the College of Nursing’s Simulation Lab.
Bearcat Mascot, Cheer Team and scholarships help celebrate Decision Day
December 12, 2025
Cincinnati media organization provided news coverage of Decision Day activities at the University of Cincinnati on Dec. 10, 2025. Surprise announcements of the 2026 Marian Spencer Scholarship recipient occurred during the day.