September 3, 2008
Chickenpox Cases Down 90 Percent
U.S. researchers say chickenpox cases have fallen by up to 90 percent in some communities since the vaccine was introduced in 1995.
The Centers for Disease Control and Prevention said the vaccine has reduced infections in every age group, including infants too young to be vaccinated but benefit from the reduced exposure to the virus, USA Today reported Tuesday.
The report found conflicting evidence on theories that the vaccine can lead to an increased risk of shingles on older adults. Two studies investigated by CDC researchers found the chickenpox vaccine had boosted shingles rates, but two other studies found no effect, the Chicago Tribune reported. Some scientists suggest the chickenpox vaccine removes a natural immune booster that once reduced the risk the the virus will reappear as shingles.