One of the smallpox vaccines available in the United States can also offer protection against mpox (aka monkeypox). But if you got a smallpox shot as a child, you’re probably no longer protected.
Mpox, formerly known as monkeypox, is transmitted through close contact with a person or animal with the virus. It causes a skin rash and flu-like symptoms, such as fever and chills.
The smallpox vaccine helps protect against mpox. Keep reading for an overview of frequently asked questions.
Monkeypox vs. smallpox
Mpox and smallpox both belong to a family of viruses known as orthopoxviruses. They have similar makeup and characteristics, and as a result, cause similar symptoms.
Smallpox was extremely deadly. Mpox is much milder than smallpox. It usually resolves on its own after a couple of weeks and is rarely fatal.
The World Health Organization declared smallpox eradicated in
Smallpox vaccines stimulate the production of antibodies that can recognize other orthopoxviruses, including mpox. As a result, smallpox vaccines also offer protection against mpox.
There are currently two smallpox vaccines available in the United States:
- JYNNEOS vaccine: The Food and Drug Administration (FDA) approved the JYNNEOS vaccine to protect against both smallpox and mpox in 2019. It’s currently the first line of protection against mpox in the United States.
- ACAM2000 vaccine: Since 2007, the ACAM2000 vaccine has been
FDA approvedto protect against smallpox. But it is not FDA approved for use against mpox. Still, people in high risk populations may use it under the FDA’s expanded drug access program.
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If you’re at risk of mpox, ask a healthcare professional about the risks and benefits of vaccination.
If you were born before 1972, you might have received the smallpox vaccine. Protection against smallpox lasts around
It’s not clear how much protection a previous smallpox vaccine offers against mpox in the context of the current outbreak. In general, childhood vaccinations are not likely to provide lifelong protection, with effectiveness decreasing over time.
But this may not be true for everyone who received the smallpox vaccine as a child. The authors of a 2020 study that included women who received the smallpox vaccine as children found that subsequent HIV infection decreased smallpox immunity later in life.
Protection against mpox is highest 2 weeks after the second dose of the smallpox vaccine. It’s not clear how long protection lasts, with research currently in progress.
The vaccine is effective both before and after exposure to mpox. It’s most effective if you get it within 4 days of exposure. If you get it within 2 weeks of exposure, it can still reduce the severity of symptoms.
The JYNNEOS vaccine has been FDA approved for the prevention of mpox since 2019.
You need two doses of the vaccine for adequate protection against mpox. You’ll receive the second dose 1 month after the first dose. JYNNEOS is most effective around 2 weeks after the second dose.
Who’s at risk of monkeypox?
Anyone exposed to the virus can get mpox. In the current outbreak, men who have sex with men have the highest risk of contracting it.
You contract mpox through close contact with someone who has it. This can include activities such as:
- touching, hugging, and kissing
- oral, anal, or vaginal sex
- prolonged face-to-face contact
The risk of contracting mpox from touching objects or surfaces touched by someone with mpox is low.
Try to also avoid sharing utensils or handling objects that belong to someone who has mpox. Finally, wash your hands often.
It’s best to take the same precautions against mpox whether you receive the vaccine or not.
Mpox is a virus that causes a skin rash, fever, chills, and other symptoms. It’s similar to smallpox but tends to be milder.
Because smallpox and mpox share similar characteristics, smallpox vaccines can also protect against mpox. The FDA currently recommends them for people exposed to mpox or at risk of future exposure.