ACAM2000 is a live vaccinia virus (a “pox”-type virus) to protect against smallpox disease. ACAM2000 uses newer technology based on cells grown in laboratories.
ACAM2000 is indicated for active immunization against smallpox disease for persons determined to be at high risk for smallpox infection.
Smallpox vaccines are no longer routine, although some soldiers and laboratory workers still are inoculated.
U.S. health officials approved ACAM2000 which is part of a government stockpile for emergency use in case of a biological attack.
Smallpox was eradicated in 1979 but many experts fear that samples of the virus, which kills at least 30 percent of its victims, were developed into biological weapons in countries such as Iraq and of the former Soviet Union.
In May, an FDA advisory panel said the vaccine was safe and effective but should only be used when there was a high risk of exposure to smallpox.
The U.S. government began stockpiling smallpox vaccine after the Sept. 11 attacks.