ST. LOUIS — On May 18, a man in Massachusetts tested positive for monkeypox, becoming the first U.S. case this year.
Monkeypox is typically found in Africa, and rare cases in the U.S. and elsewhere are usually linked to travel there. According to the Centers for Disease Control and Prevention (CDC), as of July 19, there were 2,107 cases of monkeypox reported in the U.S., including nine in Missouri and 200 in Illinois.
Social media users have posted a lot of questions about monkeypox, and some are wondering if they already have some protection.
THE QUESTION:
Do people who were vaccinated for smallpox prior to 1972 have some immunity to monkeypox?
THE SOURCES:
-Dr. Sharon Frey, clinical director of Saint Louis University's Center for Vaccine Development
-Dr. Paul Offit, director of Children's Hospital of Philadelphia's Vaccine Education Center
-New York State Department of Health
THE ANSWER:
We can verify people who received the smallpox vaccine before 1972 were also protected against monkeypox. But it doesn't mean you’re still protected. A booster vaccine is needed to ensure immunity to both viruses.
WHAT WE FOUND:
Prior to 1972, the smallpox vaccination was routine in the United States. Our experts say it also protected people from monkeypox because both diseases are part of the poxvirus family.
The vaccine experts told the Verify team studies have shown some people can have partial protection against these diseases for decades.
However, Dr. Frey said, "This does not mean that someone would be completely protected from disease if exposed, but it could mean that a response to a booster vaccination would provide a quicker response."