By Marie Rosenthal, MS
The CDC’s Advisory Committee on Immunization Practices recommended that the mpox vaccine Jynneos, by Bavarian Nordic, be added to the routine vaccination schedule for certain adults who are at high risk for acquiring the disease.
The recommendation, for those ages 18 years and older, is an interim recommendation that the committee will revisit in two to three years. Groups at risk include gay, bisexual and other men who have sex with men; and transgender or nonbinary people who have experienced one of the following within the past six months: a new diagnosis of at least one sexually transmitted infection, had more than one sex partner, had sex at a commercial sex venue, or had sex in association with a large public event in a geographic area where mpox transmission is occurring. In addition, people who are sexual partners of people with any of the risks described above should also be vaccinated.
The ACIP had previously recommended the vaccination be given during an outbreak, after the recent global outbreak of mpox, which started in 2022. The outbreak “primarily affected gay, bisexual and other men who have sex with men; was associated with person-to-person spread via close skin-to-skin contact, including sex; and certainly deaths occurred primarily among persons with severe immunocompromise,” explained Pablo J. Sanchez, MD, a professor of pediatrics, Division of Neonatal-Perinatal Medicine, Division of Pediatric Infectious Diseases, The Ohio State University – Nationwide Children’s Hospital, Columbus, Ohio.
The United States recorded more than 30,800 cases and 54 deaths, with most of the deaths occurring among people with advanced HIV.
Jynneos vaccine is composed of a replication-deficient vaccinia virus, which is given as a two-dose series administered subcutaneously 28 days apart. “Its effectiveness was assessed by comparing immunologic response to that for ACAM 2000 [vaccine],” said Dr. Sanchez, who is also the chair of the ACIP Mpox Workgroup.
“It was licensed for prevention of both smallpox and mpox, and it is recommended currently for persons with HIV and other immunocompromising conditions, and it's licensed for persons 18 years of age or older.”
The National Institutes of Health is researching its safety and immunogenicity for those 12 to 17 years of age.
The ACIP considered the wider, routine recommendation to increase vaccination coverage among people at risk for the disease, and to prevent or minimize ongoing disease.
In addition, the World Health Organization is embarking on the development of a program to eliminate human-to-human transmission of mpox, and although not considered by the workgroup in making its recommendations, Dr. Sanchez said the U.S. recommendation may “support any upcoming strategy from the World Health Organization with respect to future elimination of mpox.”
In addition, Dr. Sanchez said, Bavarian Nordic is more likely to commercialize the vaccine, which would help ensure a steady supply, if the vaccine were to be on a routine schedule. This would enable the transition of the vaccine from U.S. government stockpiles intended for emergency preparedness to the commercial sector.
Although the United States is still experiencing cases, the case counts since the beginning of the global outbreak have greatly diminished. Only a handful of states did not report mpox during the recent outbreak, according to Faisal Syed Minhaj, PharmD, MPH, DABAT, an epidemiologist in the Poxvirus and Rabies Branch, Division of High Consequence Pathogens and Pathology, of the CDC.
The CDC has consulted on about two to six new cases per month over the last six months, he said, adding that Black people, those living with HIV and those experiencing homelessness are disproportionately affected.
“Mpox cases and deaths continue to be reported domestically and globally,” Dr. Minhaj said. Only 25% of people who are eligible for vaccination have been vaccinated, and modeling suggests that without vaccination, transmission of mpox will continue with sporadic outbreaks.
It is hoped that having the vaccination become part of routine care would remove some of the stigma and facilitate a consultation during appointments with a clinician, according to Dr. Sanchez.
