Although the incidence of Hib disease
has decreased in countries implementing childhood vaccination (2), invasive disease caused by NTHi has become more prominent during the same period, especially among newborns and the elderly (3-6).
In 97% of healthy unvaccinated adults, circulating IgG antibodies against Hib capsular polysaccharide were above the level ensuring longterm protection against invasive Hib disease
Based on animal and human studies, anti-PRP levels of [greater than or equal to]0.15 [micro]g/ mL and [greater than or equal to]1.0 [micro]g/mL provide protection from invasive Hib disease
in the short- and long-term, respectively.
Following the introduction of the Hib glycoconjugate vaccine, the annual incidences of invasive Hib disease
and carriage (subclinical infection) in children aged <5 years decreased dramatically in countries where vaccination was implemented [8, 9].
* A graph for Haemophilus influenzae type B vaccine (Hib), indicates that the incidence of invasive Hib disease
had decreased from 40-100 per 100,000 children in 1980 at the time of the introduction of the vaccine, down to fewer than 1 per 100,000 in 1990.
The EPI aims to protect children against nine vaccine preventable diseases; Polio, Tuberculosis, Pertussis, Hepatitis- B, Diphtheria, Tetanus, Hib disease
, Measles and pneumonia, of which pneumonia is the latest addition.
* A routine vaccine is available to prevent Hib disease
For the Hib component of the Menhibrix vaccine, immune responses in infants and toddlers following vaccination with Menhibrix were found to be comparable to immune responses in infants and toddlers who received another FDA-approved vaccine against invasive Hib disease
. For the meningococcal component, data showed that the vaccine induced the production of antibodies at levels considered to be predictive of protection against invasive meningococcal disease caused by serogroups C and Y, the FDA said.
It is reportedly the first combination vaccine to help prevent meningococcal serogroups C and Y and Hib disease
(15) Additional surveillance data from Sweden show high VE against invasive Hib disease
, with incidences of 0.5 per 100 000 in 1997 and 0.16 per 100 000 in 2008.
Lone et al (1), have cautioned about the introduction of pentavalent vaccine, that also includes vaccine against Haemophilus influenzae type b (Hib), citing several studies in support of the lower Hib disease
burden in India, which stems from errors in interpretation of scientific literature.