Chickenpox Vanishing Thanks to Vaccine
Feb. 5, 2002 -- The familiar red, itchy spots that come with chickenpox may soon become a rare sight thanks to a vaccine. A new study shows the once-common childhood disease is rapidly declining in areas where the majority of children receive the vaccination.
The highly contagious disease is caused by the varicella zoster virus. Although it rarely causes complications in children, the disease can lead to more serious illnesses such as pneumonia and encephalitis (inflammation of the brain) in adults. In addition, children who have chickenpox as children may suffer from a painful condition called shingles later in life.
Before the chickenpox vaccine became available in 1995, the virus caused more than 4 million cases of chickenpox, 11,000 hospitalizations, and 100 deaths every year. Since the introduction of the vaccine, the coverage rate among children aged 19 to 35 months has grown to about 68% nationwide in 2000, although vaccination requirements vary by state. The vaccine is designed to be given in one dose to children between 12 and 18 months and to older children who have not had the disease.
The study, published in TheJournal of the American Medical Association, examined three large communities in California, Texas, and Pennsylvania where between 74%-84% of the children aged 19 to 35 months had received the vaccine by 2000. Researchers found the number of chickenpox cases reported in these areas dropped dramatically -- between 71% and 84% -- from 1995 to 2000.
"The decline in disease was greatest in preschool children; however, declines occurred in every age group including infants and adults, indicating reduced transmission of varicella zoster virus in these communities," write the authors. The number of chickenpox-related hospitalizations also declined during the study period.
Currently, researchers say there is not a nationwide system for reporting chickenpox cases, which makes measuring the nationwide impact of the varicella vaccine difficult. In this case, the CDC worked with state and local health departments to institute surveillance programs in the three communities studied.
Although some parents initially resisted vaccinating their children for the relatively mild disease, researchers say the vaccine has been proven safe. The authors say use of the vaccine has increased rapidly and will continue to grow as states establish more surveillance systems to monitor vaccination coverage.-->