A randomized trial to determine the tolerability and immunogenicity of a quadrivalent meningococcal glycoconjugate vaccine in healthy adolescents.

BACKGROUND: Because of the well-documented increased risk of meningococcal disease among adolescents, vaccination is recommended for this population in many countries, including the United States. This study compared the tolerability and immunogenicity in adolescents of a candidate quadrivalent meningococcal CRM197 glycoconjugate vaccine against serogroups A, C, W-135, and Y (MenACWY-CRM) with that of the licensed unconjugated quadrivalent polysaccharide vaccine (MPSV4). METHODS: This phase II study was conducted in the United States among 524 adolescents aged 11-17 years in 2 stages, with different randomization schemes. The first 334 participants, enrolled in Stage 1, were randomized (1:1) to receive either MenACWY-CRM(+) (with adjuvant) or MPSV4. The next 190 participants, enrolled in Stage 2, were randomized (4:1) to receive either MenACWY-CRM(-) (without adjuvant) or MPSV4. Safety data were collected using diary cards and active surveillance. Human complement serum bactericidal activity (hSBA) titers were measured 1 and 12 months postvaccination. RESULTS: MenACWY-CRM and MPSV4 vaccines were well tolerated (local reactions, 63%-71% vs. 60%-62%; systemic reactions, 44%-56% vs. 46%-59%, respectively). One month postvaccination, similar hSBA titers were observed with the adjuvanted and nonadjuvanted MenACWY-CRM. The immunogenicity of MenACWY-CRM(-), measured by geometric mean titer, was significantly (P < 0.05) greater than that of MPSV4 for all 4 vaccine serogroups at 1 month. The percentage of subjects with hSBA titers > or =1:4 was also significantly greater (P < 0.01) for MenACWY-CRM(-) recipients for serogroups A, C, and Y and noninferior for W-135. The proportions of MenACWY-CRM(-) recipients with hSBA titers > or =1:4 to the vaccine serogroups at 1 month were 84% to 96% and geometric mean titers were 34 to 100. The percentage of subjects with hSBA titers > or =1:4 was significantly (P < 0.01) greater than MPSV4 for serogroups C, W-135, and Y 12 months postvaccination. CONCLUSIONS: MenACWY-CRM was well tolerated and immunogenic, with evidence of persistence of bactericidal antibodies for at least 12 months postvaccination.

Immunogenicity of a tetravalent meningococcal glycoconjugate vaccine in infants: a randomized controlled trial.

CONTEXT: Immunization with a meningococcal tetravalent (serogroup ACWY) glycoconjugate vaccine is recommended for all US adolescents. However, the currently licensed vaccine is poorly immunogenic in infancy, when the highest rates of disease are observed. OBJECTIVE: To determine the immunogenicity of a novel tetravalent CRM(197)-conjugated meningococcal vaccine (MenACWY) in infants. DESIGN, SETTING, AND PARTICIPANTS: Randomized, open-label, controlled study of 225 UK and 196 Canadian 2-month-olds from August 2004 to September 2006. INTERVENTION: UK infants received a primary course of MenACWY (at 2, 3, and 4 months or 2 and 4 months) or Neisseria meningitidis serogroup C monovalent meningococcal glycoconjugate vaccine (MenC) (at 2 and 4 months). All received MenACWY at 12 months. Canadian infants received MenACWY at 2, 4, and 6 months or 2 and 4 months; at 12 months they received MenACWY, a plain tetravalent polysaccharide vaccine, or no vaccine. MAIN OUTCOME MEASURE: Percentage of infants with a human complement serum bactericidal activity (hSBA) titer >or=1:4 after a primary course of MenACWY and after a 12-month booster. Safety and reactogenicity of MenACWY were also assessed. RESULTS: According to the prespecified per-protocol analysis, the percentages (95% CIs) of MenACWY 2-, 3-, and 4-month recipients with hSBA titers >or=1:4 after primary immunization were serogroup A, 93% (84%-98%); C, 96% (89%-99%); W-135, 97% (90%-100%); and Y, 94% (86%-98%). With a post hoc intention-to-treat analysis with imputed values for missing data, these values were unchanged for serogroups C and Y; for serogroup A, values were 92% (84%-97%), and for W-135, 97% (91%-99%). For the per-protocol analysis of MenACWY 2-, 4-, and 6-month recipients, the percentages (95% CIs) of responders were A, 81% (71%-89%); C, 98% (92%-100%); W-135, 99% (93%-100%); and Y, 98% (92%-100%). With the imputed value analysis, these values were A, 83% (74%-89%); C, 98% (93%-99%); W-135, 99% (94%-100%); and Y, 98% (92%-99%). At least 84% of MenACWY 2- and 4-month recipients achieved hSBA titers >or=1:4 for serogroups C, W-135, and Y after primary immunization, as did at least 60% for serogroup A (per-protocol and imputation analysis). At least 95% of primary and booster MenACWY recipients achieved hSBA titers >or=1:4 for serogroups C, W-135, and Y at 13 months, as did at least 84% for serogroup A (per-protocol and imputation analysis). During the primary immunization course, postimmunization pain on leg movement was observed in 2% of UK MenACWY 2- and 4-month recipients and 4% of MenC 2- and 4-month recipients; a temperature of 38 degrees C or greater was observed in 4% and 2% in these groups, respectively. CONCLUSION: MenACWY is well tolerated and immunogenic in infancy. Trial Registration clinicaltrials.gov Identifier: NCT00262002.

Effect of aluminum adjuvants on safety and immunogenicity of Haemophilus influenzae type b-CRM197 conjugate vaccine.

OBJECTIVE: The present study was carried out to evaluate the safety and immunogenicity of the Haemophilus influenzae type b-CRM197 (Hib-CRM197) conjugate vaccine in relation to the change of adjuvant from aluminum hydroxide to aluminum phosphate (AlPO4). METHODS: The present study was a clinical phase II, observer-blind, randomized, multicenter, controlled study. Subjects were healthy infants aged 6-12 weeks, eligible for expanded program of immunization (EPI) routine vaccination and admitted to Hacettepe University Department of Social Pediatrics and Gülveren Health Center, Ankara. A total of 520 healthy infants were randomized in a 2:2:1 ratio to receive at either Chiron Hib/AlPO4 vaccine or VaxemHib (aluminum hydroxide adjuvant) vaccine or HibTiter (no adjuvant). Vaccines were administered simultaneously with routine diphtheria, tetanus and pertussis (DTaP) and oral polio vaccine (OPV) vaccines at 2, 4 and 6 months of age. Blood samples for anti-plain polysaccharide (PRP) antibody measurement were collected before the first vaccination and 1 month after the last vaccination. After each vaccination parents filled out a diary for 7 days. RESULTS: Out of 520 subjects enrolled, 514 received three doses and were included for safety analysis. Local and systemic reactions occurred with low and similar frequencies in all groups. Only erythema was more common in Chiron Hib/AlPO4 vaccine (19, 10, 11% in Chiron Hib/AlPO4, VaxemHib and HibTiter, respectively, P < 0.05). Nine serious adverse events were reported in seven cases of which none were related to vaccines. A total of 504 subjects were included in the immunogenicity analysis. The three vaccines were highly immunogenic and equivalent in terms of percentage of acquisition of long-term protective levels. The anti-PRP geometric mean titers were 9.9, 8.3 and 5.14 micro g/mL, respectively (P < 0.05). CONCLUSIONS: The use of aluminum compounds adjuvants in Hib-CRM197 conjugate vaccines does not impact the safety profile, while it does increase the magnitude of anti-PRP antibody titers.