Induction of immunologic memory following primary vaccination with the 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine in infants.

BACKGROUND: Induction of immunologic memory was assessed following primary vaccination with 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV). METHODS: Infants were randomized (1:1) to receive 3 doses of PHiD-CV or 7vCRM (7-valent CRM197-conjugated pneumococcal conjugate vaccine [PCV]) at 2, 3, and 4 months of age followed by 23-valent pneumococcal polysaccharide vaccine (23vPS) booster dose at 11 to 14 months of age. Pneumococcal geometric mean antibody concentrations (GMCs) and opsonophagocytic activity (OPA) geometric mean titers were measured. RESULTS: Postprimary immune responses were consistent with those in previous PHiD-CV and 7vCRM studies. Following 23vPS boosting, vaccine serotype-specific antibody GMCs increased 6.5- to 33.3-fold and 4.8- to 32.2-fold versus prebooster in the PHiD-CV and 7vCRM groups, respectively. Postbooster OPA titers increased 2.8- to 38.8-fold and 2.6- to 58.9-fold, respectively. Postbooster antibody GMCs exceeded postprimary levels but, for some serotypes, postbooster OPA geometric mean titers were lower than postprimary in both groups. An additional dose of the same PCV received for priming was administered to 52 children aged 46 to 50 months, resulting in higher responses versus postprimary vaccination for all serotypes, but not always higher than post-23vPS booster. CONCLUSIONS: Induction of immunologic memory following PHiD-CV priming was confirmed. Additional PCV boosting in 4-year-olds did not provide strong evidence of hyporesponsiveness induced by previous 23vPS boosting. However, our results did not rule out depletion of the memory B cell pool following 23vPS vaccination, resulting in subsequent attenuated immune responses, and therefore support the use of PCV rather than 23vPS for booster vaccination in the second year of life.

Response to primary and booster vaccination with 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine in Korean infants.

BACKGROUND: This randomized single-blind study in Korea evaluated noninferiority of the 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) versus the 7-valent pneumococcal conjugate vaccine (7vCRM) when both were coadministered with H. influenzae type b (Hib) conjugate vaccine, as opposed to coadministration with diphtheria-tetanus-acellular pertussis-based combination vaccines in previous studies. METHODS: Infants received 3 primary doses at 2, 4, and 6 months and a booster dose at 12 to 18 months of PHiD-CV (N = 374) or 7vCRM (N = 129), both coadministered with Hib vaccine. Immune responses were measured 1 month postdose 3 and postbooster using 22F-inhibition enzyme-linked immunosorbent assay and functional opsonophagocytic activity assay. RESULTS: PHiD-CV-induced antibody responses against each of the vaccine pneumococcal serotypes and protein D. Noninferiority to 7vCRM was demonstrated for all 10 PHiD-CV serotypes in terms of percentages of subjects reaching an antibody concentration ≥0.2 µg/mL after primary vaccination. Postprimary and postbooster, percentages of subjects with antibody concentration ≥0.2 µg/mL or opsonophagocytic activity titer ≥8 were generally consistent between groups for each pneumococcal serotype common to both vaccines. The safety and reactogenicity profiles of PHiD-CV and 7vCRM were generally comparable after both primary and booster vaccination. CONCLUSIONS: In this Korean study, 3-dose PHiD-CV priming followed by a booster dose was immunogenic for all 10 vaccine pneumococcal serotypes and protein D. Noninferiority to 7vCRM in terms of enzyme-linked immunosorbent assay threshold responses postpriming was demonstrated. The safety and reactogenicity profiles of both vaccines when coadministered with Hib vaccine were generally comparable.

Immunogenicity of 10-valent pneumococcal nontypeable Haemophilus Influenzae Protein D Conjugate Vaccine when administered as catch-up vaccination to children 7 months to 5 years of age.

BACKGROUND: We evaluated catch-up vaccination schedules with 10-valent pneumococcal nontypeable Haemophilus influenzae Protein D Conjugate Vaccine (PHiD-CV). METHODS: In this open, controlled study, children stratified into 4 age groups (N = 150 each) were vaccinated with PHiD-CV: (a) <6 months reference group: 3 primary doses with booster at 12 to 15 months, (b) 7 to 11 months: 2 doses and booster at 12 to 15 months, (c) 12 to 23 months: 2 doses, and (d) 2 to 5 years: 1 dose. Serotype-specific pneumococcal responses were measured by 22F-inhibition enzyme-linked immunosorbent assay (ELISA) and opsonophagocytic activity (OPA) assay. RESULTS: In the 7 to 11 months group postbooster antibody geometric mean concentrations (except for 2 serotypes) and OPA geometric mean titers (GMTs) were in the same ranges or higher relative to postbooster values in the <6 months reference group. Following 2 doses in the 12 to 23 months group, the percentages reaching threshold levels for ELISA (except for serotypes 6B and 23F) and OPA (except for serotype 1) were comparable or higher than <6 months reference postbooster values. Antibody geometric mean concentrations and OPA GMTs, while comparable or higher than reference postprimary values, were for some serotypes lower than reference postbooster values. Following 1 dose in the 2 to 5 years group ELISA responses were lower than the reference group for several serotypes. CONCLUSIONS: A catch-up PHiD-CV schedule of 2 doses and booster for children 7 to 11 months of age was acceptable. For children 12 to 23 months of age, 2 doses seem to provide adequate priming although a booster dose might confer further benefit. Responses following 1 dose in children 2 to 5 years of age suggest that 2 doses may be preferable.

Safety and immunogenicity of a booster dose of the 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine coadministered with DTPw-HBV/Hib and poliovirus vaccines.

The safety and reactogenicity profiles of the 10-valent pneumococcal conjugate vaccine, PHiD-CV, and 7vCRM were comparable within the Philippines and Poland when coadministered as a booster dose with DTPw-HBV/Hib and poliovirus vaccines to toddlers primed with the same vaccines. Robust immune responses for all 10 vaccine pneumococcal serotypes and protein D following PHiD-CV booster vaccination were indicative of effective priming.