MONDAY, July 25 (HealthDay News) -- The varicella vaccine has nearly wiped out deaths from chickenpox in the United States, a new study shows.

The vaccine, introduced in a one-dose form in 1995, has reduced deaths from chickenpox by 88 percent in all age groups and by 97 percent in young people 20 and under, according to the study from the National Center for Immunization and Respiratory Diseases.

"This is one of our success stories," said Dr. Charles Shubin, medical director of the Children's Health Center of Mercy FamilyCare in Baltimore, who is familiar with the study.

In 2006, a second dose was added to the vaccination roster, but the decrease in deaths occurred largely during the time when just one shot was recommended, the researchers found. While chickenpox-related deaths are now relatively rare, the new two-dose regimen may eliminate them altogether, they said.

The double dose will further reduce sick days and medical care associated with chickenpox and its complications, the study authors said.

The Centers for Disease Control and Prevention, the American Academy of Pediatrics and the American Academy of Family Physicians recommend that children receive two doses of the varicella vaccine. But in recent years, there has been some pushback from parents about childhood immunizations -- largely because of unfounded fears about a link between autism and the measles-mumps-rubella (MMR) vaccine. As a result, measles and some other diseases are making comebacks.

Experts said they hope the findings will reassure anxious parents and alert them to the life-saving benefits of varicella vaccination.

Dr. Bruce Hirsch, attending physician for infectious diseases at North Shore University Hospital in Manhasset, N.Y., said the study provides "powerful information."

Deaths began declining almost immediately after the varicella vaccine was introduced. "This vaccine has saved about 80 lives per year," he said.

Dr. Gail Demmler-Harrison, professor of pediatrics-infectious disease at Baylor College of Medicine in Houston, often saw the children who became seriously ill from chickenpox, some of whom died.

"We don't see severe varicella anymore," she said. "There is a common misconception that chickenpox is a benign inconvenience of childhood and a rite of passage, but it almost always leaves lasting foot prints and there is a lot of suffering with plain old chickenpox as well as how it [affects] the family," she said.

"The risks of varicella and its complications are real, and the risks of vaccine are minimal," she added.

According to the study, published in the August issue of Pediatrics, chickenpox led to about 105 deaths a year during the pre-vaccine years of 1990 to 1994. Between 2002 and 2007, the annual average number of chickenpox deaths was the lowest ever reported, with 14 deaths recorded in 2007 and just 13 the year before.

Still unknown is whether the two doses in children is enough to ward off shingles, which occurs when the virus that causes chickenpox (varicella-zoster) is reactivated. Individuals who have had the chickenpox are at risk for shingles, and this risk increases with advancing age.

"We don't know if immunization in childhood is going to make a difference in adult shingles because it hasn't been long enough," said Shubin, who is also an associate professor of pediatrics at the University of Maryland in Baltimore.

"Whether or not the kids who had two shots when they were young need something else when they become older adults, that remains to be seen," he said.

More information

For more information about the varicella vaccine, visit the U.S. Centers for Disease Control and Prevention.