600 Kenyan children aged 12-59 months were vaccinated at days 0 , 60 and 180 in a double-blind randomized controlled trial according to the following vaccine sequence : Group A : PHiD-CV , PHiD-CV , diphtheria/tetanus/acellular pertussis vaccine ( DTaP ) ; Group B : PHiD-CV , DTaP , PHiD-CV ; Group C : hepatitis A vaccine ( HAV ) , DTaP , HAV .