HAEMOPHILUS INFLUENZA TYPE B OROPHARINGEAL CARRIAGE
AMONG DAY-CARE CHILDREN SUBMITTED TO IMMUNIZATION WITH HAEMOPHILUS
OLIGOSACCHARIDE CONJUGATE VACCINE - HBOC
Soares M-C S, Weckx L Y, Santos O P, Ouriques D M,
Pracanica A, Pinto M-I M, Weckx L L M
Universidade Federal de Sao Paulo (UNIFESP)- Escola
Paulista de Medicina, Sao Paulo, Brazil
Objective: this report
evaluates the oropharyngeal carriage of Haemophilus influenzae type b (Hib)
n day-care children before and after immunization with oligosaccharide
conjugate vaccine (HbOC) against this agent. The possible occurrence of
herd immunity is also discussed.
Methods: 56 children from
day-care center (A) were vaccinated against Hib with HbOC (Hibtitter).
Oropharingeal swab samples were collected before vaccination and one year
after. In this group, blood samples were obtained for Hib serologic
evaluation (ELISA). 62 children from another day-care center (B) were not
vaccinated against Hib and received Hepatitis B instead (control group).
Oropharyngeal swabs were collected before and one year after in this group,
also.
Results: the prevalence of
Hib carriage in children in day-care (A) decreased from 10.71% to zero one
year after Hib immunization. Seroprotective levels of antibodies were
present in this group. In the control group - day-care (B) - the prevalence
of Hib carriage was 11.29% and remained the same in the second sample.
Conclusion: Hib oligosaccharide
conjugate vaccine HbOC have led to a reduction in oropharyngeal carriage in
children that received the vaccine. The recent introduction of routine Hib
vaccination did not cause impact on the oropharyngeal carriage in non
vaccinated children.