- To demonstrate that ProQuad® can be administered concomitantly with a booster dose of Infanrix® hexa to healthy children 12 to 23 months of age without impairing either the antibody response rates to measles, mumps, rubella, varicella, hepatitis B and Haemophilus influenzae type b; or to the 3 pertussis antibody titres measured at 42 days following vaccination.