ACTHIB Rx

Two clinical trials have compared the anti-PRP antibody responses to 3 Haemophilus influenzae type b conjugate vaccines in children. Infants were immunized with ActHIB vaccine and other Haemophilus influenzae type b conjugate vaccines at 2, 4, and 6 months of age. In one study, 83% of patients administered ActHIB achieved an anti-PRP antibody titer of ≥1.0mcg/mL after the third dose. In the second study, 97% of children administered ActHIB achieved an anti-PRP antibody titer of ≥1.0mcg/mL after the third dose. 

Among Native American children, the administration of a 3-dose series of ActHIB vaccine at 6 weeks, 4 months, and 6 months of age resulted in 75% of patients achieving an anti-PRP antibody titer of ≥1.0mcg/mL at 7 months of age. Native American populations have had high rates of H. influenzae type b disease and have been observed to have low immune responses to Haemophilus influenzae type b conjugate vaccines.

The immunogenicity of ActHIB was evaluated In 4 separate studies in children 12 to 24 months of age who had not previously received Haemophilus influenzae type b conjugate vaccination. Study participants were administered a single dose of ActHIB vaccine. Among 12 to 15 month old patients, 90.2% achieved an anti-PRP antibody titer of ≥1.0mcg/mL. Among 17 to 24 month olds, 81.5% achieved an anti-PRP antibody titer of ≥1.0mcg/mL. Post immunization responses were measured at approximately 1 month after vaccination.

ActHIB has been found to be immunogenic in patients with sickle cell disease. Following 2 doses, given at 2-month intervals, 89% of children with sickle cell disease were reported to have anti-PRP antibody titers of ≥1.0mcg/mL.