Monkeypox vaccine: FDA authorizes change in how vaccine is given, in order to stretch supply

“I think we’re going to see that we will likely still run out of vaccines before we run out of arms,” Dr. Demetre Daskalakis, the White House’s assistant national response coordinator, said Tuesday.

Moving “as quickly as possible”

He added at a briefing Tuesday, “we encourage jurisdictions to utilize alternative dosing method as quickly as possible, and we’ll be your partner in this step every step of the way.”

The move comes less than a week after the Biden administration declared monkeypox a public health emergency, which gives the FDA and other government health agencies more flexibility to fight the spread of the virus.

Earlier Tuesday, US Department of Health and Human Services Secretary Xavier Becerra issued a determination to pave the way for the FDA’s move.

Prevention remains important

The CDC is launching an outreach program to ease the transition to the new strategy, expanding its education and information efforts for public health officials and health care providers. Vaccine equity will be a key part of this message, as will training and outreach on how to use the special needle for intradermal vaccination.

Officials also emphasized that people should continue to take steps to protect themselves from the monkeypox virus even after they’re vaccinated, especially those in the hard-hit population of gay and bisexual men and other men who have sex with men. This includes avoiding skin-to-skin contact with someone who may be infected and limiting the number of sex partners.

“Really, prevention for monkey pox is multidomain,” Daskalakis said. “And so as people are working to get vaccinated … we really want to give people options and clear guidance of what to do between the first and second dose and also to be aware that it does take time after the second dose to also achieve adequate protection.”

Jynneos is given as two doses at least four weeks apart. Officials said Tuesday that people who have gotten a first dose subcutaneously can get the second intradermally.

Research will continue

“The skin has special cells that are very good at helping a vaccine stimulate the body’s immune system,” he wrote.

These cells, called dendritic cells, are better able to produce an immune response, said Dr. Daniel Griffin, an infectious disease specialist at Columbia University.

“They live in the skin, and they’re better at teaching the immune system what they need to respond to,” he said.

A 2015 study found a similar immune response when the vaccine was given intradermally in doses one-fifth the size of those given subcutaneously. Side effects like redness, itchiness and swelling were more common with the intradermal method, but there was less pain.

Jynneos has also been found to be safe and effective in people with conditions that weakened their immune system, Califf said Tuesday.

However, the existing research on the vaccine focuses on recipients’ immune response, not on whether it actually prevents cases of monkeypox.

“There is no traditional assessment of this vaccine … because there weren’t smallpox cases, and the monkeypox outbreaks before this were not large enough to really do a clinical trial,” Dr. Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, said Tuesday. “We want to collect outcome data, as we do with all vaccines. And I’d also point out that the NIH will be mounting a clinical trial and is working through the logistics of that now.”

The move to allow vaccination in children is based on findings around its use in adults, as well as data on pediatric smallpox vaccination, the FDA says.

The agency isn’t authorizing intradermal vaccination in kids for two reasons: “First of all, we want to make sure we get it right, and we don’t have the data in children that we have in adults,” Marks said. “Second of all, as a practicing physician — I know I’m not a pediatrician; I’ve treated pediatric patients at times — we have had to give this vaccine to the youngest of children, and … giving an intradermal injection to a baby is actually just a little more challenging at times.”