Dryvax Seropositives #2 (Expanded Trial)
The study seeks to further 1) evaluate safety in previously vaccinated adults between the ages of 32-70 who are vaccinated with undiluted Dryvax, and 1:5 and 1:10 dilutions; 2) define with very high precision the proportion of individuals who respond with a "take" 6-11 days after vaccination with undiluted Dryvax and Dryvax diluted 1:5; 3) define with good precision the proportion of individuals who respond with a "take" with a 1:10 dilution of Dryvax and; 4) explore correlations between "takes/no takes" and immune responses in all vaccine dilution groups.
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Primary Purpose: Prevention
|Official Title:||A Multicenter, Double Blind, Randomized Dose-Response Study of Dryvax Vaccine Against Smallpox in Previously Vaccinated Adults|
|Estimated Study Completion Date:||October 2004|
This study will evaluate the safety and immunogenicity of Dryvax vaccine against smallpox and its dilutions (1:5 and 1:10) in previously, but remotely, vaccinated adults. Both serologic and cell-mediated immune responses will be evaluated (the latter on a small subgroup of volunteers). The study will be conducted at five clinics in the U.S., commencing at the University of Rochester in New York. Approximately 927 volunteers between the ages of 32 and 70 years who were previously vaccinated against smallpox (but not since 1989) will be randomized to receive Dryvax vaccine undiluted, diluted 1:5 or diluted 1:10. Subjects will be involved in the trial for 8 to 16 weeks.