Chickenpox Vaccine Slashes Virus by 90 Percent

Doctors urge a two-shot schedule, but some parents won't allow one.

ByABC News
January 28, 2009, 2:11 PM

Sept. 2, 2008— -- While researchers now say the chickenpox vaccine has slashed the occurrence of the disease in children by 90 percent, infectious disease experts remained concerned that too few parents take the disease seriously enough to get their kids vaccinated.

In a study released Tuesday in the journal Pediatrics, researchers from the U.S. Centers for Disease Control and Prevention report that the plummeting reports of chickenpox (also known as varicella) between 1995 and 2005 has dragged down chickenpox-related hospitalizations by 75 percent and reduced deaths by 74 percent -- with the greatest improvements in young children.

"The U.S. varicella vaccination program has dramatically reduced varicella incidence and related complications, hospitalizations and deaths," the authors conclude.

But they add that the effectiveness of a single dose of the vaccine -- about 85 percent -- is not sufficient to stop the spread of the virus in "high contact" settings, such as schools. They therefore recommend that a two-dose schedule be adopted for all children.

But infectious disease experts worry that too many parents may neglect to have their kids vaccinated for chickenpox -- in many cases because they believe the viral disease is not harmful.

"In my failing memory, chickenpox was responsible for 100-200 deaths per year in the U.S.," said Dr. James King, professor of pediatrics at the University of Maryland School of Medicine.

"It would be a virtual certainty that chickenpox would become widespread again if there were a reduction of the use of the varicella vaccine," he said. "It just amazes me that vaccines are not valued as they have been one of the most successful advances in medicine."

Dr. Gary Freed, director of the Division of General Pediatrics for the University of Michigan Health System, agrees.

"The public should [understand] how many hospitalizations and deaths were avoided by the use of the vaccine," he says.