(Editor’s note: The AAFP approved the emergency use authorization for intradermal adminitration of Jynneos for adults on Aug. 12, following an expedited review of the evidence. This story and headline have been updated to reflect the decision. The Academy's monkeypox webpage has been updated with the the latest information, and a video from the CDC on how to administer the Jynneos vaccine intradermally has been added as a resource at the end of this story.)
August 12, 2022, 3:35 p.m. News Staff — The AAFP on Aug. 12 approved the FDA’s Aug. 9 emergency use authorization for Jynneos, a vaccine already approved for the prevention of monkeypox and smallpox in adults 18 years and older, that allows health care professionals to administer the vaccine intradermally to adults considered to be at high risk for monkeypox infection.
The intradermal technique, a practice sometimes referred to as fractional dosing or dose-sparing, is expected to significantly increase the available number of Jynneos doses.
“Basically, a vial can be split into five separate doses instead of one dose,” explained Jonathan Temte, M.D., Ph.D., M.S., associate dean for public health and community engagement and a professor in the Department of Family Medicine and Community Health at the University of Wisconsin-Madison School of Medicine and Public Health, during an AAFP Virtual Town Hall on monkeypox, also held Aug. 9.
“Jynneos tends to be a relatively well-tolerated vaccine, and now with the dose-sparing, I think we’ve gone from 1.6 (million) to actually about 8 million potential doses out there, and I think there’s going to be a lot of effort to acquire more vaccine,” Temte added.
Jynneos was initially approved in 2019 as a two-dose series given 28 days apart, with the vaccine administered subcutaneously at an injection volume of 0.5 mL.
The EUA still requires a two-dose series, but allows for the vaccine to be administered intradermally, with an injection volume of 0.1 mL, in individuals 18 years and older at high risk of monkeypox infection.
The EUA also allows for Jynneos to be administered to younger individuals who are at high risk for infection. In these individuals, Jynneos should be administered subcutaneously as a full two-dose series at 0.5 mL.
The EUA was published shortly after HHS Secretary Xavier Becerra issued a public health determination that permitted EUAs for monkeypox vaccines.
The department’s action “will allow FDA to exercise additional authorities that may increase availability of vaccines to prevent monkeypox while continuing to ensure the vaccine meets high standards for safety, effectiveness and manufacturing quality,” Becerra explained in an HHS release.
FDA Commissioner Robert Califf, M.D., floated the idea of dose-sparing at a news briefing last week, explaining that intradermal vaccination would create “a little pocket” where the vaccine could reside.
“There’s some advantages to intradermal administration, including an improved immune response to the vaccine,” Califf said. “It’s important to note that overall safety and efficacy profile will not be sacrificed with this approach.”
In addition to the HHS and FDA actions, the CDC has updated its interim clinical considerations for the use of Jynneos and another monkeypox vaccine, ACAM2000, during the current outbreak.
The Academy’s Commission on Health of the Public and Science conducted an expedited review of the EUA and the updated interim clinical guidance recommendations. On Aug 12 the Commission made a recommendation for approval, which the AAFP Board chair accepted.
More than 10,300 cases of monkeypox have been confirmed in the United States, according to latest data from the CDC.
Visit the Academy’s monkeypox webpage for the latest information about the outbreak for family physicians.