Background: Lot-to-lot consistency study assessing primary series vaccination with a new, fully liquid, DTaP–IPV–Hep B–PRP-T vaccine (Hexaxim™ - an AcXim family vaccine), incorporating the new Hansenula polymorpha–derived Hep B antigen (Sanofi Pasteur), co-administered with Prevenar™ and Rotarix™. Methods: Phase III, randomized, observer-blind, two-centre study. Subjects received Hexaxim (Group 1: N = 1002 [3 lots-pooled]) or Infanrix hexa™ (Group 2: N = 338) at 2,4,6 months-of-age, co-administered with Prevenar (PCV7: 2, 4, 6 months) and Rotarix (2, 4 months). Hep B was given at birth. Antibody concentrations or titers were measured pre-(Hep B, D, PT, FHA) and 1 month post-(all valences) primary series for Hexaxim and Infanrix hexa. Equivalence of Hexaxim lots was tested. Non–inferiority analyses were performed for Group 1 versus Group 2 for seroprotection (SP: anti- Hep B, PRP, D, T, and polio 1/2/3) and vaccine response (VR: anti-PT and FHA) rates. Anti-PCV7 (7 months) and anti-rotavirus IgA (5 months) were also assessed. Safety after each dose was compared descriptively. Results: Equivalence was demonstrated for the Hexaxim lots, so Group 1 data were pooled for non-inferiority testing (per protocol analysis set). For all SP and VR rates, Group 1-minus-Group 2 non-inferiority was demonstrated (lower 95% CI bound for each difference was greater than the pre-specified non–inferiority margin). Anti-Hep B GMCs were similar in Groups 1 and 2 (3013 and 2766 mIU/mL); anti-PRP was higher in Group 1 (3.56 versus 2.24 μg/mL). There were no clinically relevant differences in the immune responses to Prevenar or Rotarix following co-administration with Hexaxim or Infanrix hexa. Reactogenicity was similar in each group and no vaccine–related SAEs were reported. Table 1: SP or VR (95% CI)Tabled 1Group 1Group 2Anti-Hep B ≥10 mlU/mL99.7 (99.1;99.9)100(98.8;100)Anti-PRP ≥ 0 15 ug/mL94.6 (93.0;96.0)95.9(93.1;97.8)Anti-Diphtheria ≥ 0.01 IU/mL100(99.6;100)100(98.8;100)Anti-Tetanus ≥ 0.01 IU/mL100 (99.6;100)100(98.8;100)Anti-Polio 1 ≥8 (1/dil)100 (99.6;100)100(98.8;100)Anti-Polio 2 ≥8 (1/dil)100 (99.6;100)100(98.8;100)Anti-Polio 3 ≥8 (1/dil)100(99.6;100)99.7(98.2;100)Anti-PT (EU/mL)97.5 (96.3;98.4)98.4 (96.3;99.5)Anti-FHA (EU/mL)99.8(99.2;100)99.4 (97.7;99.9) Open table in a new tab Conclusion: The new DTaP-IPV-Hep B-PRP-T vaccine is immunogenic and safe following co-administration with Prevenar and Rotarix, and similar to the licensed comparator.