| Title | Ten year follow-up of healthy children who received one or two injections of varicella vaccine. | | Author(s) | Kuter B, Matthews H, Shinefield H, Black S, Dennehy P, Watson B, Reisinger K, Kim LL, Lupinacci L, Hartzel J, Chan I, Study Group for Varivax | | Institution | Merck Research Laboratories, PO Box 4, West Point, PA 19486, USA. barbara_kuter@merck.com | | Source | Pediatr Infect Dis J 2004 Feb; 23(2):132-7. | | MeSH | Age Distribution
Antibodies, Viral
Chickenpox
Chickenpox Vaccine
Child
Child, Preschool
Comparative Study
Enzyme-Linked Immunosorbent Assay
Female
Follow-Up Studies
Herpes Zoster
Herpesvirus 3, Human
Humans
Immunity
Immunization Schedule
Incidence
Infant
Male
Probability
Research Support, Non-U.S. Gov't
Risk Assessment
Sex Distribution
Time Factors
Vaccination
Vaccines, Attenuated
| | Abstract | BACKGROUND: The rate of varicella and persistence of varicella antibody after a one dose vs. a two dose regimen of varicella virus vaccine live Oka/Merck (VARIVAX; Merck & Co., Inc., West Point, PA) in approximately 2000 children were compared during a 9- to 10-year follow-up period.
METHODS: Children 12 months to 12 years of age with a negative history of varicella were randomized in late 1991 to early 1993 to receive either one or two injections of varicella vaccine given 3 months apart. Subjects were actively followed for varicella, any varicella-like illness or zoster and any exposures to varicella or zoster on a yearly basis for 10 years after vaccination. Persistence of varicella antibody was measured yearly for 9 years.
RESULTS: Most cases of varicella reported in recipients of one or two injections of vaccine were mild. The risk of developing varicella >42 days postvaccination during the 10-year observation period was 3.3-fold lower (P < 0.001) in children who received two injections than in those who received one injection (2.2% vs. 7.3%, respectively). The estimated vaccine efficacy for the 10-year observation period was 94.4% for one injection and 98.3% for two injections (P < 0.001). Measurable serum antibody persisted for 9 years in all subjects.
CONCLUSIONS: Administration of either one or two injections of varicella vaccine to healthy children results in long term protection against most varicella disease. The two dose regimen was significantly more effective than a single injection. | | Language | eng | | Pub Type(s) | Clinical Trial
Journal Article
Randomized Controlled Trial
| | PubMed ID | 14872179 |
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