Chicken pox vaccine reduced related deaths by 88%

By Dr. Ananya Mandal, MDJul 25 2011

According to the latest study, the varicella vaccine has nearly wiped out deaths from chickenpox in the United States.

The vaccine was introduced in a one-dose form in 1995. It 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.

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

The team of researchers found that although in 2006 a second dose was added to the vaccination roster, the decrease in deaths occurred largely during the time when just one shot was recommended. 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.

According to recommendations from the Centers for Disease Control and Prevention, the American Academy of Pediatrics and the American Academy of Family Physicians, children should receive two doses of the varicella vaccine.

“The impressive decline in varicella deaths can be directly attributed to successful implementation of the 1-dose vaccination program,” write study researcher Mona Marin, of the CDC, and colleagues in Pediatrics. “With the current 2-dose program, there is potential that these most severe outcomes of a vaccine-preventable disease could be eliminated.”

In recent years there have been some 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 say experts as parents refuse these vaccines for their children. 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, added, “We don't see severe varicella anymore. 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…The risks of varicella and its complications are real, and the risks of vaccine are minimal.”

The study appeared in the August issue of Pediatrics. It said 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.

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.

“However, this should be interpreted bearing in mind that varicella causes few deaths and that the main benefit of the vaccination program comes from a reduction of lost work and medical care associated with cases and severe complications,” write the researchers. “Nevertheless, varicella deaths are a powerful reminder of the importance of vaccination for prevention.”