Biography
Biography: Dr. Adi Zarei
Abstract
Haemophilus influenzae occupies the nasopharynx as a commensal opportunistic
bacterium. The most recurrent and serious disease associated with H. influenzae type
b (Hib) infection is meningitis, which can result in neurological sequelae. The
worldwide incidence of Hib meningitis in children aged <5 years was 57/100,000 in
the pre-vaccination era and this has dramatically reduced in the post-vaccination era.
The first Hib capsular polysaccharide (CPS) vaccine was licensed in 1985;
subsequently, conjugate vaccines have been developed and licensed. Serum anti-CPS
antibodies confer immunity against invasive Hib disease. An anti-CPS concentration
of ≥0.15 g/ml is believed to be a serological indication for short-term immunity
protection against invasive Hib disease, while a concentration of ≥1.0 g/ml one
month after the completion of the primary immunization course is believed to be
protective. Since serum anti-CPS antibodies are strongly associated with protection,
the measurement of antibody levels and a review of circulation data in worldwide
populations are the main steps toward proper assessment of vaccine-induced
immunity; either direct or herd. Several populations worldwide remain vulnerable to
Hib-related infections. We expect that this review on the circulation of anti-Hib
antibodies and the incidence of Hib worldwide will serve as a valuable reference for
immunologists, epidemiologists, and public health executives.