Post-Marketing Safety Surveillance of a Childhood Pentavalent Diphtheria–Tetanus–Acellular Pertussis–Polio and Haemophilus influenzae Type B (DTaP-IPV//Hib) Vaccine in South Korea

INTRODUCTION: PENTAXIM™ (Sanofi), DTaP-IPV//Hib, a pentavalent combination vaccine for protection against diphtheria, tetanus, pertussis, poliomyelitis, and invasive infections caused by Haemophilus influenzae type b, has been licensed in South Korea by the Ministry of Food and Drug Safety (MFDS) on May 9, 2016, and is currently used in routine vaccination. The aim of this phase IV study, conducted as a post-licensure commitment in South Korea, was to evaluate the safety of the DTaP-IPV//Hib vaccine when administered in infants at 2, 4, and 6 months of age in the real-world clinical practice. METHODS: This multicenter, observational, post-marketing surveillance (PMS) study was conducted in real-world practice in South Korea. Infants aged 2 months or older were enrolled across seven centers from July 31, 2018 to February 11, 2020. The study outcomes included occurrence, time to onset, duration, intensity, and causality assessment (for unsolicited adverse events [AEs] only) for several pre-listed solicited injection-site and systemic reactions, unsolicited AEs, and serious adverse events (SAEs). RESULTS: Data from 619 participants were included in the safety analysis. Overall, 618 AEs were reported by 273 (44.1%) participants consisting of 121 solicited injection-site reactions (15.4%), 344 solicited systemic reactions (24.6%), and 153 unsolicited AEs (15.7%) of which, 124 were unexpected AEs (12.9%) (regardless of intensity). None of the unsolicited AEs were reported to have a causal relationship with the study vaccine. One SAE of pyrexia (solicited reaction) was reported. Most AEs were of mild intensity, and all participants recovered. CONCLUSION: This PMS study of the DTaP-IPV//Hib vaccine confirmed its safety profile in a real-life setting in South Korea and justified that the vaccine is well tolerated when used in infants aged 2 months or older for the primary series.