761. Safety and immunogenicity of two mixed primary infant immunization schedules of pentavalent diphtheria, tetanus, acellular pertussis, inactivated poliomyelitis (DTaP-IPV) and Haemophilus influenzae type B (Hib) vaccines, at 2, 4 months and 6 months of age  
Session: Oral Abstract Session: Pertussis Vaccines and Challenges
Friday, October 21, 2011: 2:15 PM
Room: 156ABC
Background:  

Two pentavalent infant vaccines are authorized in Canada: Pediacel® (P)(Sanofi Pasteur) and Infanrix™-IPV-Hib (I) (GlaxoSmithKline Biologicals), which contain five and three component aP antigens respectively: pertussis toxoid (PT), filamentous hemagglutinin (FHA), pertactin (PRN), and fimbrial agglutinogens (FIM) 2 and 3 v. PT, FHA and PRN. Interchangeability of P and I for the toddler booster dose has been shown, but the safety and immunogenicity of mixed primary infant schedules is unknown.

Methods: 

In a double-blind multicentre trial, two month old healthy infants were randomized to either a PPI or IPP schedule at 2, 4 and 6 months of age. Solicited local and systemic adverse events (AE) were collected by parent diary daily day 0-7 and unsolicited AE day 0-28 after each dose. Serious AE were collected to day 180. PRP (Hib) seroprotection, and geometric mean concentration (GMC) and ≥4-fold antibody rise (4FAR) to PT, FHA, PRN and FIM was assessed before dose (D)1 and 28 days  after D3.

Results:  

127 infants were randomized to IPP and 126 to PPI. Any injection site reaction post dose 3 was more common with PPI than IPP: (46.0 v 31.7, p=0.026). PPI had more frequent swelling (26.4 v 10.7% day 0-7, p=0.002) and tenderness (35.2 v. 20.5% day 0-7, p=0.011). Mild systemic AE post dose 3 (decreased appetite, crying, vomiting, irritability) were more common in PPI than IPP, with no difference in fever or drowsiness.  Percentage of children with PRP ≥0.15mg/ml post dose 3 was higher in the IPP than the PPI group (98.3 95% CI 94.1, 98.8 v 86.1%, 95% CI 78.6, 91.7, p =0.001); 4FAR and GMC were also statistically significant higher. IPP elicited higher FIM 4 FAR (76.9 v 58.8) and GMC (158.2 v. 46.2) than PPI. PT GMC was higher with IPP than PPI (99.1 v. 76.3 p<0.00). By contrast higher FHA occurred in PPI than IPP (4FAR 89.1 v 78.6, p=0.034; GMC 111.9 v. 78.9, p<0.001). Anti-PRN responses and PT 4FAR were not different between groups.

Conclusion: 

Mixed 2, 4, 6 month infant schedules had different immunogenicity and reactogenicity, with a PPI schedule being more reactogenic, and less immunogenic for PRP and FIM antigens at 7 months. It is preferable to complete the primary infant 3-dose vaccine series with the same vaccine, rather than considering infant vaccines as interchangeable.

 


Subject Category: I. Adult and Pediatric Vaccines

Joanne Langley, MD1, Scott Halperin, MD2,3,4,5,6, E Rubin, MD7, Craig White, MD8, Jill Mutch, BScN9, Shelly McNeil, MD10, Donna MacKinnon-Cameron, MMath8 and Bruce Smith, PhD5, (1)Canadian Center for Vaccinology, Dalhousie University and the IWK Health Centre, Halifax, NS, Canada, (2)Dalhousie University, Canadian Center for Vaccinology, IWK Health Centre and Capital Health, Halifax, NS, Canada, (3)Clinical Trials Research Center, Halifax, NS, Canada, (4)Dalhousie University IWK Health Centre, Halifax, NS, Canada, (5)Dalhousie University, Halifax, NS, Canada, (6)IWK Health Centre, Halifax, NS, Canada, (7)Pediatircs, Montreal Children Hospital, Montreal, QC, Canada, (8)Canadian Center for Vaccinology, IWK Health Centre, Halifax, NS, Canada, (9)Clinical Evaluation Unit, Canadian Center for Vaccinology., Halifax, NS, Canada, (10)Dalhousie University, Canadian Center for Vaccinology, IWK Health Centre, Halifax, NS, Canada

Disclosures:

J. Langley, None

S. Halperin, Sanofi Pasteur: Investigator, Research grant
GlaxoSmithKline: Investigator, Research grant

E. Rubin, None

C. White, None

J. Mutch, None

S. McNeil, sanofi pasteur: Grant Investigator, Research support

D. MacKinnon-Cameron, None

B. Smith, None

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