In a multicenter study, 4,209 children were randomized to receive either KINRIX or INFANRIX and IPV vaccines concomitantly. Subjects also received MMR vaccine administered concomitantly at a separate site. The schedule of administration for KINRIX was a single dose in children ages 4 to 6 who previously received 4 doses of INFANRIX, 3 doses of IPV vaccine, and 1 dose of MMR vaccine.