Intradermal Vs. Subcutanous

Intradermal Vs. Subcutaneous Vaccination

On August 9th, 2022 the FDA issued an emergency use authorization to begin giving the Monkeypox vaccine (JYNNEOS) intradermally for people ages 18+ who do not have a history of keloid scarring.

What is the difference between intradermal and subcutaneous vaccination?

  • Intradermal: A shallow injection that is injected just under the skin. It will create a bump (sometimes called a “wheal”) under the skin which indicates the injection was successful. The bump may cause some mild irritation or redness but will resolve. Don’t mess with or put pressure on the bump and allow it to heal on its own.
  • Subcutaneous: An injection that is injected into the fat layer, deeper than an intradermal injection but not as deep as an intramuscular (in the muscle) injection. Can be injected in the fat in the back of the arm or less commonly in the fat on the stomach. May also cause mild irritation and redness that will heal on its own.

Why did the FDA choose to switch Monkeypox vaccination to intradermal injections?

  • When administrating an intradermal injection, the “dose” is still the same as a subcutaneous injection but has a lower volume/amount used while still being effective. This allows for more people to get vaccinated since less volume is being used per person.
  • Skin has more immune-building cells so it has a quicker immune response as opposed to fatty tissue. Your skin is used to responding quickly and efficiently to heal cuts/abrasions/etc so when the vaccine is given under the skin, the immune building cells don’t need as much vaccine to build a response.

If I received a subcutaneous injection for my first vaccine will I get an intradermal injection instead for my second dose?

  • Yes, you will receive an intradermal injection for your second dose even if you had it done subcutaneously the first time. You’ll get the same level of protection after a second dose with either route of administration but in order to allow for more community-members to be vaccinated we have switched to intradermal injection.

Last updated 10/06/22