Varicella vaccine effectiveness in the US vaccination program: a review.

Abstract

Varicella vaccine (Varivax, Merck) has been available in the United States since 1995. We reviewed published results of postlicensure studies of vaccine effectiveness. Among 19 studies, 17 reported on the effectiveness of vaccine received before exposure, and 2 reported on effectiveness after exposure. Studies used retrospective and prospective cohort, case-control, and secondary attack rate (household contact) designs. The majority of estimates assessed protection against clinically diagnosed varicella. One dose of varicella vaccine was 84.5% effective (median; range, 44%-100%) in preventing all varicella and 100% effective (mean and median) in preventing severe varicella. When administered after exposure, varicella vaccine was highly effective in preventing or modifying varicella. Although 1 dose of varicella vaccine has provided excellent protection, a higher degree of effectiveness is needed in order to interrupt transmission and to prevent outbreaks in settings with high contact rates. Monitoring the effectiveness of the newly recommended 2-dose childhood vaccine schedule for varicella vaccine is a priority.

• Authors: Jane F Seward, Mona Marin, Marietta Vázquez
• Journal: The Journal of infectious diseases (J Infect Dis) Vol. 197 Suppl 2 Pg. S82-9 (Mar 01 2008) ISSN: 0022-1899 [Print] United States
• PMID: 18419415 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Review)

Chemical References

• Chickenpox Vaccine

Topics

• Adolescent
• Case-Control Studies
• Chickenpox (epidemiology, prevention & control)
• Chickenpox Vaccine (administration & dosage, therapeutic use)
• Child
• Child, Preschool
• Cohort Studies
• Disease Outbreaks (prevention & control)
• Humans
• Immunization Programs
• Prospective Studies
• Retrospective Studies
• Treatment Outcome
• United States (epidemiology)
• Vaccination