Background: Recent reviews have highlighted the unpredictability of immunologic interference when multivalent conjugated vaccines are coadministered with other pediatric vaccines.
Objective: To evaluate immunogenicity, safety, and reactogenicity of the 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV; Synflorix, GlaxoSmithKline Biologicals) and DTPa-IPV-Hib (Pediacel, Sanofi Pasteur MSD) when coadministered as a 3-dose primary vaccination course.
Material and methods: In a single-blind, single-center, randomized controlled trial in the Netherlands, healthy infants (n = 780) were randomly assigned (1:1:1) to receive either (1) PHiD-CV + DTPa-HBV-IPV/Hib (Infanrix Hexa, GlaxoSmithKline Biologicals), (2) PHiD-CV + DTPa-IPV-Hib, or (3) 7-valent pneumococcal conjugate vaccine (Prevenar/Prevnar, Pfizer Inc.) + DTPa-IPV-Hib at 2, 3, and 4 months of age. Blood samples were collected 1 month after dose 3. Diary cards were used to record safety and reactogenicity.
Results: Antibody concentrations elicited by PHiD-CV coadministered with DTPa-IPV-Hib were noninferior to those following DTPa-HBV-IPV/Hib coadministration for 9 of 10 vaccines pneumococcal serotypes and protein D. For serotype 18C (conjugated to tetanus toxoid), the antibody concentration was higher with DTPa-HBV-IPV/Hib coadministration (1.73 vs. 1.07 μg/mL). The percentages of infants with antibody concentrations ≥0.2 μg/mL (68.9%-100% in the PHiD-CV + DTPa-HBV-IPV/Hib group vs. 64.9%-100% in the PHiD-CV + DTPa-IPV-Hib group) and with measurable opsonophagocytic activity (56.1%-100% in the PHiD-CV + DTPa-HBV-IPV/Hib group vs. 61.1%-100% in the PHiD-CV + DTPa-IPV-Hib group) were comparable for all serotypes in both PHiD-CV groups. Group differences in antibody responses to the DTPa-IPV-Hib antigens remained within the predefined limit for noninferiority. Safety and reactogenicity profiles were comparable across groups.
Conclusions: : PHiD-CV and DTPa-IPV-Hib were immunogenic and well tolerated when coadministered as a 3-dose primary vaccination course.