NIH Trial Evaluating Mpox Vaccine in Adolescents

GW one of 18 clinical sites around the US testing mpox vaccine in youth

April 19, 2023

Colorized transmission electron micrograph of mpox virus particles

Colorized transmission electron micrograph of mpox virus particles. Credit: NIAID

WASHINGTON (April 19, 2023)--The National Institutes of Health trial to evaluate the mpox (previously known as monkeypox) vaccine JYNNEOS has now entered the next stage and is studying the immune responses to and the safety of the vaccine in adolescents. The George Washington University is one of 18 clinical trial sites across the United States that have launched this stage testing the JYNNEOS vaccine.

The JYNNEOS vaccine was approved by the U.S. Food and Drug Administration for use in adults in 2019 and, in 2022, was authorized for use in people under 18 years of age on an emergency use basis. The latest stage of the trial, which is sponsored by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, will look to see if the vaccine is safe and triggers an immune response in adolescents ages 12 to 17 that is comparable to adults ages 18 to 50 years. GW’s participation is funded through a contract with Frederick National Laboratory for Cancer Research, operated by Leidos Biomedical Research in Frederick, Maryland, which provides scientific support to NIH.

“We are excited to have launched the next stage of this clinical trial, which can help determine if this vaccine can be used to protect adolescents should there be another large outbreak in the United States or some other part of the world,” David Diemert, clinical director of the George Washington University Vaccine Research Unit and professor of medicine at the GW School of Medicine and Health Sciences, said. 

The GW Vaccine Research Unit is a collaboration between the Departments of Medicine and Microbiology, Immunology and Tropical Medicine located at the George Washington University School of Medicine and Health Sciences, and the GW Medical Faculty Associates. The GW Vaccine Research Unit conducts clinical trials of experimental products that are being developed for the prevention of infectious diseases.

The clinical investigators at GW and the other sites plan to test 135 adults ages 18 to 50 who will serve as a comparison group in this stage of the study. The researchers will also recruit about 315 adolescents ages 12 to 17 years. All of the recruits will get the standard dose of the vaccine delivered subcutaneously, Diemert said.

The trial will last for 13 months and investigators will check for safety and to see if the antibody response in adolescents in the study are comparable to that of adults.

Mpox historically occurs in West and Central Africa, but in 2022, a large outbreak began in the United States and other countries around the world where mpox is uncommon. The virus spreads through close contact with an infected person or animal.

Although kids in the United States rarely get mpox, experts say children and teens can and do get this painful and sometimes deadly disease. 

“Having a safe and effective vaccine at the ready would help prepare the United States and other countries for the next outbreak of this disease,” Diemert said.

Interested volunteers can email [email protected], call (202) 994-1599, or visit redcap.link/gwmpoxstudy for more details.  

Interested volunteers can also visit clincialtrials.gov and search identifier NCT05740982 for more information about the trial, including a list of sites. Please do not call or email the NIAID News and Science Writing Branch to inquire about enrolling in this trial.