Can a child still get chickenpox after vaccination?
About 1-4% of vaccinated children per year develop “breakthrough” disease when exposed to naturally occurring chickenpox. This occurs in children with low antibody levels after vaccination. Their disease tends to be mild with fewer skin lesions, lower fevers, and a faster recovery. How protective is the vaccine? 86% effective against all forms of chickenpox disease and 100 % effective against moderate to severe disease. Since licensure 6 years ago, the incidence of chickenpox has decreased in all age groups, including unimmunized persons. This suggests herd immunity. The vaccine works–we just need to vaccinate more children. How long does the vaccine provide immunity? Antibody levels have been followed for at least 10 years in children given the currently licensed vaccine, and for more than 20 years in children given earlier formulations. Nearly all children maintain antibody levels for as long as 20 years. Will we produce a population of susceptible adults? As more and more children a
