Haemophilus influenzae type b disease in the era of conjugate vaccines: Critical factors for successful eradication.

Slack, Mary; Esposito, Susanna; Haas, Hervé; Mihalyi, Attila; Nissen, Michael; Mukherjee, Piyali; Harrington, Lauriane

INTRODUCTION Prior to implementation of Haemophilus influenzae type b (Hib)-conjugate vaccination programs in the 1990s, Hib was the commonest cause of bacterial meningitis in children aged <5 years. While the burden of all Hib disease has significantly decreased in the post vaccination era, Hib still accounted for >29,000 deaths worldwide in children aged <5 years in 2015. AREAS COVERED We reviewed literature data on the most widely used Hib vaccines and vaccination strategies which led to the global prevention and control of Hib disease and aim to highlight important factors for continued disease control and elimination in the future. EXPERT COMMENTARY More than 90% of countries worldwide have implemented Hib-conjugate vaccination in their national immunization programs. Vaccines containing Hib polyribosylribitol phosphate (PRP) conjugated with tetanus toxoid (Hib-TT) are the most commonly used. Neisseria meningitidis outer membrane protein complex of PRP (Hib-OMP) is also used. Although the kinetics of the immune response varies with Hib vaccine and schedule used, high control of Hib disease was observed in all settings/scenarios. Further improving global Hib vaccination coverage may result in disease elimination.