The vaccine can now be given to high-risk adults intradermally, that is, between the layers of the skin, instead of subcutaneously, or under the skin, as has been given up until now. This will allow providers to obtain five doses from a standard one-dose vial.
The new US also allows subcutaneous vaccination in people under 18 who are at high risk of infection.
“In recent weeks, the monkeypox virus has continued to spread at a rate that has made it clear that our current vaccine supply will not meet current demand,” said FDA Commissioner Dr. Robert M. Califf, in a statement. “The FDA quickly explored other scientifically sound options to make vaccine access easier for all affected people. By increasing the number of doses available, more people who want to get vaccinated against monkeypox will now have the opportunity to do it.”
The move comes less than a week after the Biden administration declared monkeypox a public health emergency, giving 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 clear the way for the FDA’s measure.
“Last week, I declared monkeypox a public health emergency to unlock additional tools to help us contain and end this outbreak and to signal to the American people that we are taking our response to the next level,” he said. said Becerra in a statement. . “Today’s action will allow the FDA to exercise additional authorities that could increase the availability of vaccines to prevent monkeypox while ensuring that the vaccine meets high standards of safety, efficacy and manufacturing quality.”
As of Monday, the US government has shipped 617,693 doses of Jynneos to states and jurisdictions. The US Centers for Disease Control and Prevention has estimated that at least 1.5 million people in the US are eligible for monkeypox vaccination.
As of Monday evening, the CDC is reporting 8,934 probable or confirmed cases of monkeypox in 49 states, Puerto Rico and the District of Columbia.
With an intradermal vaccine, “basically, you stay on the skin; you don’t go through the skin,” said Dr. Daniel Griffin, an infectious disease specialist at Columbia University.
The use of a smaller dose by intradermal injection has been done with influenza and rabies vaccines, said epidemiologist Dr. Jay Varma told CNN in an email.
“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, Griffin said.
“They live in the skin and are better at teaching the immune system what to respond to,” he said.
“If you can give the monkeypox vaccine intradermally, you can give a smaller dose. … They would just have to have some kind of demonstration that you get the same immune response,” he said.
CNN’s Jeremy Diamond, Brenda Goodman and Virginia Langmaid contributed to this report.