Intradermal Vs. Subcutanous

Intradermal Vs. Subcutaneous Vaccination

On August 9th, 2022 the FDA issued an emergency use authorization to begin giving the Mpox vaccine (JYNNEOS) intradermally for people ages 18+ who do not have a history of keloid scarring. As of summer of 2023, both intradermal and subcutaneous have been found to be equally as effective and some clinics offer either option.

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 Mpox vaccination to intradermal injections in 2022?

  • 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 allowed for more people to get vaccinated since less volume is being used per person.

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

  • It depends on the clinic. Because vaccine is more available now than in 2022, some clinics allow you to choose between the subcutaneous or intradermal option. Other clinics may still choose to rely on intradermal injections.