Comparing the meningococcal serogroup C immune response elicited by a tetanus toxoid conjugate quadrivalent meningococcal vaccine (MenACYW-TT) versus a quadrivalent or monovalent C tetanus toxoid conjugate meningococcal vaccine in healthy meningococcal vaccine-naïve toddlers: A randomised, controlled trial.

MenACYW-TT (MenQuadfi®) is a quadrivalent meningococcal tetanus toxoid conjugate vaccine licensed in Europe for use in individuals ≥12 months. This study assessed whether serogroup C immune responses with MenACYW-TT were at least non-inferior, or superior, to those of quadrivalent meningococcal ACWY (MCV4-TT; Nimenrix®) and monovalent meningococcal C (MenC-TT; NeisVac-C®) vaccines in toddlers (12-23 months). In this modified, double-blind Phase III study (NCT03890367), 701 toddlers received one dose of MenACYW-TT (n = 230), MCV4-TT (n = 232) or MenC-TT (n = 239). Serum bactericidal assays with human (hSBA) and baby rabbit (rSBA) complement were used to measure anti-meningococcal serogroup C antibodies at baseline and 30 days post-vaccination. A sequential statistical approach was used for primary and secondary objectives. For the primary objectives, superiority of serogroup C was assessed in terms of hSBA seroprotection rates (defined as titers ≥1:8) and GMTs for MenACYW-TT compared to MCV4-TT, and rSBA GMTs compared to MenC-TT. The safety of all vaccines within 30 days post-vaccination was described. When administered as a single dose to meningococcal vaccine-naïve healthy toddlers the superiority of the MenACYW-TT serogroup C immune response versus MCV4-TT was demonstrated for hSBA GMTs (ratio 16.3 [12.7-21.0]) and seroprotection (difference 10.43% [5.68-16.20]); and versus MenC-TT in terms of rSBA GMTs (ratio 1.32 [1.06-1.64]). The safety profiles of a single dose of MenACYW-TT, MCV4-TT and MenC-TT were similar. In meningococcal vaccine-naïve toddlers, MenACYW-TT induced superior immune responses to serogroup C versus MCV4-TT in terms of hSBA seroprotection and GMTs and versus MenC-TT in terms of rSBA GMTs.

Evaluation of a Hexavalent-Pentavalent-Hexavalent Infant Primary Vaccination Series Followed by a Pentavalent Booster Vaccine in Healthy Infants and Toddlers.

BACKGROUND: This study assessed a pediatric mixed hexavalent diphtheria (D)-tetanus (T)-acellular pertussis (aP)-inactivated poliovirus (IPV)-hepatitis B (HB)-Haemophilus influenzae b [polyribosylribitol phosphate (PRP-T)]-pentavalent (DTaP-IPV//PRP-T)-hexavalent primary series schedule followed by a pentavalent booster. METHODS: Healthy infants (N = 265) who had received a prior HB vaccination received a fully liquid, hexavalent vaccine (DTaP-IPV-HB-PRP-T) at 2 and 6 months of age and a reconstituted pentavalent vaccine (DTaP-IPV//PRP-T) at 4 months of age. Coadministered vaccines were pneumococcal vaccine at 2 and 4 months (and optionally at 6 months of age), rotavirus vaccine at 2, 4, 6 months and meningococcal serogroup C vaccine at 2 months. At 18 months, participants received DTaP-IPV//PRP-T and pneumococcal vaccine boosters. Immunogenicity was assessed using validated assays and safety by parental reports. RESULTS: For the hexavalent and pentavalent vaccines, the primary series and booster immune responses in terms of seroprotection and vaccine response rates were high for all antigens (generally > 99% and > 95% for the primary series and booster, respectively) and prebooster antibody persistence was good for all antigens (in particular, 92.4% of participants had prebooster anti-HB antibody ≥ 10 mIU/mL). The incidence of solicited reactions was lower after the booster vaccination (56.9%-73.1%) than the primary series (76.6%-97.4%); there were few vaccine-related unsolicited adverse events (1.9% and 1.5% for the primary series and booster, respectively), none led to participant discontinuation and none was serious. CONCLUSIONS: This study provides data that allow recommending authorities to consider the use of a sequential hexavalent-pentavalent-hexavalent primary vaccination series followed by a pentavalent booster in coadministration with other common childhood vaccines.

Antibody persistence in pre-school children after hexavalent vaccine infant primary and booster administration.

OBJECTIVE: Antibody persistence evaluation for all antigens of a fully liquid DTaP-IPV-HB-PRP~T vaccine at 3.5 and 4.5 y of age following different primary series and booster schedules in South Africa and Latin America. METHODS: Participants had completed one of two previous studies (Study 1-South Africa; Study 2-Latin America). In Study 1, participants who had not received HB vaccine at birth received a 6-10-14 week primary series of DTaP-IPV-HB-PRP~T or DTwP/PRP~T-Hib+HB+OPV and a third group who had received HB vaccine at birth received a 6-10-14 week primary series of DTaP-IPV-HB-PRP~T; all received a booster (15-18 months) of the primary series vaccine(s) except for HB in the DTwP/PRP~T-Hib group. In Study 2, participants received HB vaccine at birth, a 2-4-6 month primary series of DTaP-IPV-HB-PRP~T or DTaP-HB-IPV//PRP~T, and a DTaP-IPV-HB-PRP~T or DTaP-HB-IPV//PRP~T booster (12-24 months). Participants were followed up at 3.5 and 4.5 y of age for antibody persistence. RESULTS: Approximately 80% of eligible participants were assessed. In Study 1, a birth dose of HB increased anti-HBs persistence (≥10 mIU/mL) following DTaP-IPV-HB-PRP~T primary and booster vaccination from 76.3% to 96.1% at 3.5 y of age and from 73.3% to 96.1% at 4.5 y of age; in Study 2, anti-HBs persistence was high and similar in each group. For the other antigens, there were no differences between groups or studies at 3.5 or 4.5 y. CONCLUSION: Good persistence of antibodies to each antigen in the DTaP-IPV-HB-PRP~T vaccine up to pre-school age, irrespective of the vaccination schedule during the first 2 y of life.

Immunogenicity and Safety of Primary and Booster Vaccinations of a Fully Liquid DTaP-IPV-HB-PRP-T Hexavalent Vaccine in Healthy Infants and Toddlers in Germany and the Czech Republic.

To support a fully liquid, diphtheria (D)-tetanus (T)-acellular pertussis (aP)-inactivated poliovirus (IPV)-hepatitis B (HB)-Haemophilus influenzae b (PRP-T) vaccine in Europe using a 2, 3, 4 month primary series and a booster at 11-15 months of age. Phase III, randomized, observer-blind studies in Germany and the Czech Republic. Participants who had not received HB vaccine were randomized to a 2, 3, 4 month primary series of DTaP-IPV-HB-PRP-T (group 1; N = 266) or a reconstituted DTaP-HB-IPV//PRP-T comparator (group 2; N = 263) and a booster of the same vaccine. Pneumococcal vaccine (PCV13) and rotavirus vaccine were coadministered at 2, 3, 4 months, and the booster was coadministered with PCV13. Noninferiority (group 1 versus group 2) was tested postprimary series for seroprotection rates (anti-HB and anti-PRP) and vaccine response rates (anti-pertussis toxin and anti-filamentous hemagglutinin). Safety was assessed by parental reports. Noninferiority was demonstrated with the lower bound of the 95% confidence interval for the difference (group 1 to group 2) being > -10% for each comparison. Primary series immune responses were high for all antigens and similar in each group. Prebooster antibody persistence was good, and there was a strong anamnestic response, both being similar for the investigational and control vaccines. Responses to PCV13 and rotavirus vaccine were similar in each group. There were no safety concerns. These data support the use of the DTaP-IPV-HB-PRP-T vaccine in a 2, 3, 4 month schedule without a birth dose of HB vaccine, with a booster dose in the second year of life administered with routine childhood vaccines.

Persistence of hepatitis B immune memory until 9-10 years of age following hepatitis B vaccination at birth and DTaP-IPV-HB-PRP∼T vaccination at 2, 4 and 6 months.

OBJECTIVE: To evaluate the long-term persistence of anti-hepatitis B surface (HBs) antibodies and the response to a HB challenge re-vaccination in children who had received a primary series of DTaP-IPV-HB-PRP∼T (Hexaxim™) or DTaP-IPV-HB/PRP∼T (Infanrix hexa™). METHODS: Two cohorts of participants who had previously received HB vaccine at birth followed by either DTaP-IPV-HB-PRP∼T or DTaP-IPV-HB/PRP∼T co-administered with PCV7 at 2, 4, 6 months of age in a randomized, Phase III, observer-blind study in Thailand, were followed up for anti-HBs antibodies (geometric mean concentrations [GMCs] and seroprotection [SP] rate [% of participants with a titer ≥10 mIU/mL]) at 12-18 months of age and 9-10 years of age. A monovalent HB challenge re-vaccination was administered at 9-10 years of age and the anamnestic response was evaluated. RESULTS: Anti-HBs GMCs and SP rates in the DTaP-IPV-HB-PRP∼T and DTaP-IPV-HB/PRP∼T groups were high and similar post-primary vaccination series (2477 mIU/mL and 99.5% and 2442 mIU/mL and 99.5%, respectively) and declined to a similar extent in each group at 12-18 months (154.5 mIU/mL and 90.8% and 162.3 mIU/mL and 96.5%, respectively). Antibody levels further declined at 9-10 years of age (13.3 mIU/mL and 49.3% and 8.0 mIU/mL and 42.9%) and a strong anamnestic response occurred in each group post-HB challenge re-vaccination (92.8% and 98.7%, respectively). CONCLUSION: The kinetics of long-term anti-HBs antibody persistence were similar following a primary series of DTaP-IPV-HB-PRP∼T or DTaP-IPV-HB/PRP∼T. The response to a subsequent HB challenge re-vaccination was strong and similar in each group, demonstrating persisting immune memory.

A Randomized Controlled Study of a Fully Liquid DTaP-IPV-HB-PRP-T Hexavalent Vaccine for Primary and Booster Vaccinations of Healthy Infants and Toddlers in Latin America.

BACKGROUND: Hexavalent diphtheria-tetanus-acellular pertussis-inactivated poliovirus-hepatitis B-Haemophilus influenzae type b (DTaP-IPV-HB-PRP-T)-containing vaccines are increasingly the standard of care. This study evaluated the primary series (NCT01177722) and booster (NCT01444781) of a fully liquid DTaP-IPV-HB-PRP-T vaccine in Latin America. METHODS: Infants (N = 1375) received hepatitis B vaccine at birth and were randomized to one of 3 batches of the investigational DTaP-IPV-HB-PRP-T or licensed control vaccine (DTaP-HB-IPV//PRP-T) at 2-4 to 6 months of age, coadministered with 7-valent pneumococcal conjugate vaccine (PCV7) (2-4-6 months) and rotavirus vaccine (2-4 months). A booster of either DTaP-IPV-HB-PRP-T or control was given at 12-24 months, coadministered with PCV7. Immunogenicity was assessed by validated assays and safety from parental reports. RESULTS: Primary series seroprotection and vaccine response rates were equivalent for DTaP-IPV-HB-PRP-T batches. For pooled batches, noninferiority to the control vaccine was demonstrated for each antigen. There were no descriptive differences in antibody persistence or booster response between DTaP-IPV-HB-PRP-T and the control. The booster responses to either vaccine following DTaP-IPV-HB-PRP-T primary series or to DTaP-IPV-HB-PRP-T following a control vaccine primary series were similar. The anti-aP component (filamentous hemagglutinin [FHA] and pertussis toxin [PT]) vaccine response and anti-Haemophilus influenzae type b (PRP) series seroprotection (≥0.15 µg/mL) rates were ≥73.0% after 2 primary series doses. Antipyretics had no effect on the immune response, and an extra (oral) polio vaccination had no effect on the antipolio booster response. Responses to PCV7 and rotavirus vaccine were similar for each coadministration. There were no safety concerns observed with any vaccine. CONCLUSIONS: These results confirm the suitability of the fully liquid DTaP-IPV-HB-PRP-T vaccine for primary and booster vaccination of infants.

Combined immunogenicity data for a new DTaP-IPV-Hep B-PRP-T vaccine (Hexaxim) following primary series administration at 2, 4, 6 months of age in Latin America.

The immunogenicity of a primary series of a new, fully liquid DTaP-IPV-Hep B-PRP-T vaccine (Hexaxim), administered at 2, 4, 6 months of age in four clinical studies is reviewed. Immunogenicity data at 1 month after the third vaccination were assessed and pooled from a total of 1270 participants (per-protocol population) in four randomized clinical trials in Argentina, Mexico, and Peru. Hepatitis B vaccine was not administered at birth. All seroprotection (D, T, polio-1, -2, -3, Hep B, PRP-T [Hib]), seroconversion (PT and FHA), and vaccine response (PT and FHA) data were high, and were similar to licensed comparators (pooled SP, SC, and VR rates were 97.1-100%, 96.0-97.0%, and 99.7-99.9%, respectively). These data show the good immunogenicity of this new hexavalent vaccine that can provide the opportunity to increase global compliance to complex pediatric vaccination schedules.