TABLE 1.

Study Design

GroupSpring Immunization, April–JuneFall Immunization, September–December30 Days After Fall Immunization60 Days After Fall Immunization
Early (N = 118)Enrollment, blood, 2002 vaccine (N = 114)2003 Vaccine (N = 108)Blood, 2003 vaccine (N = 102)
Standard (N = 126)Enrollment2003 Vaccine (N = 105)Blood, 2003 vaccine (N = 100)Blood (N = 99)
Nonrandomized standard (N = 40)Enrollment, 2003 vaccine (N = 40)Blood, 2003 vaccine (N = 38)Blood (N = 32)
  • — indicates that no child in this group was enrolled at this time.