Decades-old smallpox vaccination may protect you against monkeypox.
If you are older, you were almost certainly vaccinated against smallpox as a child, leaving behind a small pea-sized scar on your arm.

The good news is that you may still be protected from monkeypox thanks to the smallpox vaccine, according to Dr. Michael Mosley, a British medical TV doctor.

Smallpox vaccination from decades ago can offer protection against monkeypox. In the UK and the US, smallpox vaccination programs continued until 1971–1972, meaning people aged 50 and above were vaccinated and will have protection, according to the Daily Mail and The New York Times.

Smallpox is related to monkeypox, and studies show the smallpox vaccine provides about 85% protection against monkeypox.

What is especially remarkable is that even decades later, when people vaccinated as children are tested again, they still show strong antibody responses against smallpox—the longest recorded case so far being someone vaccinated more than 90 years ago, according to the Daily Mail.

Older adults who were vaccinated may still get infected but are more likely to recover—with only mild symptoms.

Dr. Luigi Ferrucci, scientific director at the U.S. National Institute on Aging, also stated that it is important to know that people vaccinated decades ago still maintain high levels of antibodies and strong virus-neutralizing capability.
A smallpox vaccination scar from childhood indicates that you will be protected from monkeypox.

He said that even if they were vaccinated 50 years ago, that protection still exists.

Dr. Anthony S. Fauci, the White House’s top infectious disease adviser, was asked about the durability of the smallpox vaccine.

He said that, of course, most vaccinated people remain protected, but the strength of that protection varies from person to person.

“We cannot guarantee that someone who was vaccinated against smallpox will still be protected from monkeypox,” Dr. Fauci said, according to The New York Times.

Should unvaccinated people be worried?

The answer is: rest assured.

Experts say that most children and adults with healthy immune systems can avoid severe illness.

Who is at higher risk?

There are two high-risk groups.
The first is infants under 6 months. But this group has not yet been affected by the current outbreak.

The second group is older adults, who may be less able to fight off monkeypox—but at least they have some degree of protection thanks to the smallpox vaccine they received decades ago, studies show, according to The New York Times.

Anne Rimoin, an epidemiologist at the University of California, Los Angeles, who has studied monkeypox in Africa, said:
“We are fortunate to have vaccines and treatments. We have the ability to contain this virus.”

Monkeypox does not spread when there are no symptoms. Dr. Rimoin said that careful monitoring, isolating infected individuals, tracing their contacts, and quarantining exposed individuals will stop the outbreak, according to The New York Times.