Efficacy Of High-Titer Live Attenuated Varicella Vaccine In Healthy Young Children

• Published in: The Journal of infectious diseases 1996-11, Vol.174 (Supplement-3), p.S330-S334
• Main Authors: Varis, Tiina, Vesikari, Timo
• Format: Article
• Language: English
• Subjects: Antibodies; Antibodies, Viral - blood; Blood; Chickenpox; Chickenpox vaccine; Chickenpox Vaccine - adverse effects; Chickenpox Vaccine - immunology; Child, Preschool; Children; Double-Blind Method; Female; Herpesvirus 3, Human - immunology; Humans; Immunity; Immunization; Infant; Male; Pediatrics; Placebos; Transcriptional regulatory elements; Vaccination; Vaccines, Attenuated - immunology
• ISSN: 0022-1899; 1537-6613
• DOI: 10.1093/infdis/174.Supplement_3.S330

The efficacy of a high-titer, reformulated varicella vaccine was studied in 513 10- to 30-monthold children. Vaccinees were randomly allocated to 5 groups to receive one of two lots of an original high-titer vaccine, one of two lots of a partially heat-inactivated vaccine, or placebo. Both vaccines were well tolerated. Seroconversion was detected in 100%and 99% of children immunized with the high- and low-titer vaccines, respectively. Sixty-five cases of serologically confirmed varicella-like disease were discovered during follow-up (mean, 29.3 months): 5 in the high-titer vaccine group, 19 in the low-titer vaccine group, and 41 in the placebo group (P≤?.005 for each difference). Thus, the protective efficacy of live attenuated varicella vaccine is dependent on vaccine titer. High-titer varicella vaccine induces excellent protection in healthy young children.