Comparison of the immunogenicity and safety of pentavalent vaccine Quinvaxem in a compact prefilled auto-disabled (cPAD) injection system versus single-dose vials in healthy infants: a phase 3, open-label, randomized, parallel-group, non-inferiority study.

OBJECTIVE: To evaluate non-inferiority of three doses of Quinvaxem in a compact prefilled auto-disabled (cPAD) injection system versus Quinvaxem in a single-dose vial administered with conventional syringe in terms of seroconversion/seroprotection rates for all antibodies (anti-hepatitis B (HB), anti-Haemophilus influenzae type b polyribosylribitol phosphate (Hib PRP), anti-diphtheria, anti-tetanus, anti-Bordetella pertussis) at 1 month after primary vaccination.

METHODS: Four hundred healthy infants aged 42-65 days were randomized (1:1) to receive Quinvaxem in cPAD or single-dose vial at 6, 10, and 12 weeks of age. Blood samples were collected before vaccination and at 1 month after the third dose to determine seroconversion/seroprotection rates. Safety was assessed from solicited and unsolicited adverse events and serious adverse events (SAEs).

RESULTS: Of the 400 infants randomized, 395 (98.8%) received all three vaccine doses. In the cPAD vs. single-dose vial groups, seroprotection rates against Hib PRP (both 98.5%), HB (92.9% vs. 93.4%), diphtheria (100% vs. 99%), and tetanus toxoids (both 100%), and seroconversion against B. pertussis (95.4% vs. 97%) were ≥92% at 1 month after the third vaccination (lower limits of 95% confidence intervals simultaneously greater than -10%). Geometric mean concentrations exceeded seroprotection/seroconversion thresholds by large margins. The incidences of induration and erythema were comparable between the groups; tenderness was slightly higher in the cPAD group (85.5% vs. 76.5%). No vaccine-related SAEs occurred.

CONCLUSIONS: Quinvaxem in cPAD was non-inferior to single-dose vial with respect to seroprotection/seroconversion rates for all antibodies. Both presentations were well-tolerated.