The deferral of the booster dose was always meant to be a temporary situation, but now that nearly 18 months have passed, we have seen several cases of Hib disease
primarily among unimmunized and partially immunized children.
As with pneumococcal disease, the greatest burden of Hib disease
lies in Asia and Africa.
Routine use of Haemophilus influenzae type b (Hib) conjugate vaccines has dramatically reduced the incidence of Hib disease
in children <5 years of age in numerous populations (1-4).
a study design where the burden of vaccine preventable Hib disease
is estimated by measuring the proportion of pneumonia and meningitis cases prevented during clinical trials of Hib conjugate vaccine, represent an important tool for estimating this undiagnosed disease burden.
CONTACT: For further information on Hib disease
and pneumococcal disease or to arrange an interview with an expert, please contact: World Health Organization, Ethiopia, Dr.
occurred primarily in children under 5 years of age in the United States prior to the initiation of a vaccine program and was estimated to account for nearly 20,000 cases of invasive infections annually, approximately 12,000 of which were meningitis.
Since the introduction of the Hib conjugate vaccine, the incidence of invasive Hib disease
in children has decreased by 99% (1, 2).
007 per cent and they speculate that the population may have 'natural immunity' to invasive Hib disease
predominantly occurred as meningitis during the pre-vaccine era in the United States, originally accounting for 50-65 percent of cases.
Hundreds of thousands of young children are dying of Hib disease
because of a lack of national Hib immunisation programmes", said Dr.
Most Hib disease
is seen as pneumonia, and estimates of Hib disease
incidence based on meningitis data consequently underestimate the true incidence in the general population (2,12).
The introduction of the Hib conjugate vaccine into national childhood immunization programs in the 1990s has resulted in a marked and sustained reduction in the incidence of invasive Hib disease
in many countries (2).