School of Public Health, NYS Department of Health Scientists Lead Research into Mpox Vaccine Effectiveness

A healthcare provider wearing PPE, glasses and a blue medical mask administers a vaccine to a patient wearing a black shirt against a plain white background.
Photo by Mat Napo / Unsplash.com

ALBANY, N.Y. (July 25, 2023) – University at Albany researchers jointly affiliated with the School of Public Health (SPH) and the New York State Department of Health (NYSDOH) have contributed to a new study on the effectiveness of the JYNNEOS mpox vaccine published in the CDC’s Morbidity and Mortality Weekly Report.

The study is the first to assess the vaccine’s effectiveness in the context of “real-world” human-to-human spread and supports ongoing guidance by the Centers for Disease Control and Prevention (CDC) and NYSDOH that two doses of the JYNNEOS vaccine offer maximum protection against mpox.  

“These findings and the innovative methods used to study the effectiveness of the JYNNEOS vaccine to prevent the spread of mpox highlight the value of real-time research in response to public health threats,” said lead author Eli Rosenberg, associate professor in the Department of Epidemiology and Biostatistics at SPH and NYSDOH Deputy Director for Science, Office of Public Health.

Until the recent mpox outbreak, which began in 2022 and incited nearly 90,000 cases reported worldwide to date, mpox had been an extremely rare disease. Sexual transmission was virtually unheard of, and the public health community had few biomedical tools with which to fight it. One of those tools was the approved and licensed JYNNEOS vaccine.

Using state-of-the-art methods and analytical tools, research led by the NYSDOH was able to evaluate the effectiveness of the vaccine in near real-time as it was implemented, adding important data to inform future efforts to prevent mpox outbreaks. Preliminary results of this study were presented at the CDC’s Advisory Committee on Immunization Practices (ACIP) meeting in February and set in motion the current mpox vaccine recommendations for outbreaks. 

“Prior to the 2022 outbreak, we had little experience using JYNNEOS to manage mpox, an infection that was previously incredibly rare in the United States," said said Rachel Malloy, assistant professor in SPH's Department of Epidemiology and Biostatistics and NYSDOH Director, Office of Sexual Health and Epidemiology. “This real-world assessment of the effectiveness of JYNNEOS during the 2022 mpox outbreak yielded promising results and the findings support our ongoing messaging that two doses of JYNNEOS offers the best protection against symptomatic infection.”

The case-control study estimated the JYNNEOS vaccine effectiveness against mpox in New York residents (outside of New York City) using data from systematic surveillance reporting. Researchers found that, while receiving one dose of the vaccine offered some protection (68.1%), getting the second dose had even higher protection (88.5%). The findings support the approved use of JYNNEOS as a two-dose series for mpox prevention.

Despite the current low number of cases and an increase in access to the JYNNEOS vaccine, mpox is still circulating and the return of mpox to communities in New York and beyond remains a very real possibility. To protect against mpox, the research team recommends taking the following precautions:  

  • Get vaccinated for mpox.  
  • Talk with sexual partners about whether they have a rash or other symptoms consistent with mpox or other SITs, and if so, seek testing and treatment.  
  • Avoid skin-to-skin contact with someone who has a rash or other mpox-related symptoms.  
  • In the event of a confirmed or suspected mpox exposure, reach out to a health care provider for guidance on treatments or other appropriate precautions.