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: Control Clin Trials 2001 Aug;22(4):438-52 |
Design of a Group-Randomized Streptococcus
pneumoniae Vaccine Trial.
Moulton LH, O'Brien KL, Kohberger R, Chang I, Reid R, Weatherholtz R,
Hackell JG, Siber GR, Santosham M.
The Center for American Indian and Alaskan Native Health, Department of
International Health, The Johns Hopkins University School of Hygiene and Public
Health, Baltimore, MD, USA
A group-randomized, double-masked, phase III trial of a Streptococcus
pneumoniae conjugate vaccine is being conducted in American Indian populations
in the southwestern United States. Approximately 9000 infants will be enrolled
in the primary efficacy cohort with vaccine allocation determined by community
of residence. The trial is designed to continue until 48 cases of invasive
pneumococcal disease due to vaccine serotypes have accumulated. Thirty-eight
geographically and socially distinct areas were randomized within blocks formed
by population size and geographic location. This design affords the opportunity
to capture the effects of herd immunity (indirect effects) by estimating the
impact of the vaccine intervention on nonimmunized infants. Group-randomized
trials have challenging design and analysis features, many of which are
discussed here in the context of the first such trial designed to lead to
licensure of a drug or biologic in the United States. Control Clin Trials 2001;
22:438-452
PMID: 11514043 [PubMed - in process]