Both terms will be used for the next year as WHO phases out usage of monkeypox.
This technique is called intradermal vaccination.
There are at least 1.6 million people in the U.S. who areestimated to be at an elevated riskfor mpox.
Verywell / Mira Norian
Protecting this whole group requires at least 3.2 million doses of the two-dose vaccine.
Only about half that amount is expected to become available before the end of the year.
The dose-sparing approach would allow the government to make thousands of doses usable for millions of people.
Verywell / Mira Norian
COVID-19 and flu vaccines, for example, areintramuscular injections.
Jynneos was initially approved in 2019 to be administered a different way: subcutaneously.
Thesubcutaneous layerof your skin, also called the hypodermis, is made up of fat and other tissues.
The newemergency use authorizationfor mpox reserves subcutaneous injection only for minors.
Jynneos is a two-dose vaccine.
Intradermal injections deliver vaccine or medication to the dermisthe topmost layer of the skin.
This technique is relatively rare because its challenging to do it correctly.
But theres a chance youve had an intradermal injection before.
Its commonly used to test for tuberculosis and allergies.
Intradermal shots are much shallower than subcutaneous or intramuscular injections.
Youll feel a quick pinch.
The resulting small, vaccine-filled welt should disappear within days.
This jumpstarts the bodys defense-building process.
Dendritic cells, which are abundant in the skin, are especially quick at shuttling antigens to immune cells.
But Does It Work Well Enough?
That study measured the level of neutralizing antibodies induced by different vaccination approaches.
Antibody levels are a key metric for understanding how well a vaccine works.
But these types of studies arent always predictive of how well the vaccine will perform in real-world controls.
Theres also a higher likelihood of error when administering the vaccine intradermally.
The FDA is presenting studies done under controlled conditions, Offit said.
In the 2015 study, fatigue was the most common side effect regardless of how Jynneos was administered.
Each group reported similar levels of muscle aches, chills, headaches, and other side effects.
Participants who received the Jynneos shot intradermally tended to have more itching and redness that lasted over two weeks.
Is a Small Dose Better Than One Dose?
TheFDA saidthis approach was not considered acceptable.
But research indicates a single dose can create a strong and long-lasting immune response.
Scientists dont actually know much about how well any of the vaccination strategies work in the real world.
Thats because Jynneos was licensed based on data from both animal experiments and immune response studies in humans.
Researchers arent sure exactly how effective this intradermal approach will be.
2021;224(8):1372-1382. doi:10.1093/infdis/jiab111
