The Advisory Committee on Immunization Practices (ACIP) to the Centers for Disease Control and Prevention (CDC), in its meeting in Atlanta today, voted to recommend a second dose of varicella (chickenpox) vaccine for children four to six years old to further improve protection against the disease.
The first dose of varicella vaccine is recommended at 12 to 18 months old.
Fifteen to 20 percent of children who have received one dose of the vaccine are not fully protected and may develop chickenpox after coming in contact with varicella zoster virus. Additionally, one dose of the vaccine may not continue to provide protection into adulthood when chickenpox is more severe. A second dose of varicella vaccine provides increased protection against varicella disease compared to one-dose. The ACIP also recommended that children, adolescents and adults who previously received one dose should receive a second dose.
“We have made great progress in reducing chickenpox during the past ten years,” said Dr. Anne Schuchat, director of CDC’s National Center for Immunization and Respiratory Diseases. “This recommendation will further reduce outbreaks of chickenpox and provide better individual protection.”
Before licensure of the varicella vaccine in 1995, each year there were about four million cases of varicella, 13,500 hospitalizations and 150 deaths. Cases of varicella have steadily declined 80 to 85 percent in surveillance sites since the licensure. From 1995 to 2001, varicella hospitalizations declined by 72 percent and deaths, among those 50 years old and younger, decreased by 75% or more.