Safety, tolerability and immunogenicity of intramuscular administration of PRP-CRM197 Hib vaccine to healthy Japanese children: An open-label trial
Takehiro Togashi, Nodoka Mitsuya, Shuji Sumino, Yohei Takanami, Takehiro Togashi, Nodoka Mitsuya, Shuji Sumino, Yohei Takanami
Abstract
Background: Japan licensed the conjugate Haemophilus influenzae type b vaccine, Vaxem™ Hib, based on clinical studies using subcutaneous injection. The present study was performed to ensure this vaccine is suitable for intramuscular injection in Japanese children.
Methods: Thirty-one healthy 2-6-month-old infants received three doses of Vaxem™ Hib by intramuscular injection at 4-week intervals and a booster dose 1 year later, concomitant with routine infant (DTaP-IPV and pneumococcal) and toddler (measles-rubella) vaccines. Immunogenicity was assessed before and after the primary series and booster dose by enzyme-linked immunosorbent assay for anti-polyribosyl-ribitol-phosphate (PRP) antibodies. Safety was assessed by medical examination and diary cards completed by the subjects' parents/legal guardians.
Results: There were no vaccine-related serious adverse events or withdrawals; all children completed the study. Four weeks after the primary series, the geometric mean anti-PRP titer (GMT) was 19.68 μg/mL, and all children had seroprotective titers (≥0.15 μg/mL) that persisted until the booster dose. Proportions of titers indicative of long-term protection (≥1.0 μg/mL) were 100% after the primary series and 77.4% before the booster. Anamnestic responses to the booster had a GMT of 51.33 μg/mL, and 100% had titers ≥1.0 μg/mL. All but one subject reported injection site reactions as resolved within 3 days of vaccination; systemic reactions due to Hib and routine vaccines were also resolved within this period.
Conclusions: Vaxem™ Hib was generally well tolerated and immunogenic in Japanese children when administered by intramuscular injection in a three-dose primary series and as a booster with concomitant routine vaccines. Clinical trial registry: Registered on Clinical Trials.gov: NCT02074345.
Keywords: Haemophilus influenzae type b; Immunogenicity; Intramuscular; Japan; Safety; Vaccine.
Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.
Source: PubMed