FDA approves new smallpox vaccination

Feb 20 2005

The U.S. Food and Drug Administration (FDA) has approved Vaccinia Immune Globulin Intravenous (VIGIV) - the first intravenous human plasma-derived product available to treat certain rare complications of smallpox vaccination.

VIGIV, licensed to DynPort Vaccine Company LLC, in Frederick, Md., is made from the pooled plasma of donors who received booster immunizations with the licensed smallpox vaccine -- Dryvax. This plasma contains increased levels of protective antibodies against the vaccinia virus, the live virus used in the currently available smallpox vaccine. The vaccinia virus is similar to the smallpox virus, but does not cause smallpox.

Because the smallpox vaccine is made with this live virus, even though it is a weakened virus, occasionally it can cause infections in susceptible vaccinated people or those in close contact with them. People with weakened immune systems or certain skin conditions are susceptible to vaccine complications. VIGIV helps treat these complications.

The Centers for Disease Control and Prevention (CDC) classifies smallpox as a disease believed to pose the greatest threat to public health from bioterrorism, along with anthrax, botulism, and plague. Historically, up to 30 percent of smallpox cases are fatal. No proven treatment exists. Thus, in people who are considered at high risk for contracting smallpox, such as those who would be called upon to respond to a bioterrorist attack using smallpox as a weapon, the benefits of the highly effective smallpox vaccine outweigh its risks. This approval of VIGIV may help minimize these risks.

The most common side effects from the smallpox vaccine such as a sore arm, fever, and body rashes, are self-limiting and do not require treatment. VIGIV would only be used for rare serious vaccine complications, such as a severe infection of the skin. Those at increased risk for these complications include people with eczema or other skin conditions, and people whose immune systems are suppressed due to diseases or medications, such as steroids or therapies for cancer.

The approval of VIGIV was based on both the safety of the product and prior evidence that the levels of protective antibodies achieved during treatment were adequate for treating complications of vaccination.

In clinical studies of VIGIV in 111 volunteers, the medicine was well tolerated. When adverse effects were noted, they were mild to moderate and included headaches, hives, and other rashes.