Is waning immunity a problem with the varicella-containing vaccines?
The length of protection/immunity from varicella-containing vaccines remains unknown. Available data from follow-up of children vaccinated in prelicensure clinical trials indicate that protection from varicella vaccine lasts for at least 25 years (Japanese data) and 14 years (U.S. data). However, most of the data concerning vaccine efficacy and persistence of antibody in vaccinees are based on research that was conducted when natural varicella infection was highly prevalent and had not been affected by wide use of the vaccine. A recently published community-based study among children 12 months to 12 years of age suggests that 1 dose vaccine-induced immunity to varicella may wane over time. Experience with other live viral vaccines (e.g., measles, rubella), however, has shown that post vaccination, immunity remains high throughout life. For these vaccines, second doses are needed to cover the small percentage of people who fail to seroconvert after the first dose (primary vaccine failur
