IMMUNIZATION OF SAUDI CHILDREN AGAINST HAEMOPHILUS INFLUENZA TYPE-B AT THE AGE OF 6 WEEKS

Objective: To study the immunogenicity of 3 doses of HbOC in 6 week ol d Saudi infants who were given either WHO DTP or FDA DTP formula. Meth ods: Six week old infants were randomized into three groups to receive 3 doses of HbOC and FDA DTP formula, HbOC and WHO DTP formula or in a control group to receive usual vaccines without HbOC at 6 weeks, 3 mo nths and 5 months. Anti body levels for PRP, tetanus, diphtheria and p ertussis were measured. Only the result of the Hib antibody will be pr esented. Results: After 3 doses no difference was found between anti-P RP either when given with FDA DTP or WHO DTP formula. Ninety two to ni nety four percent of the vaccinated children in our sample acquired th e protective level after the third dose. Thirty percent of the unvacci nated children do not have anti-Hib maternal antibody at the age of 6 months. No negative interactions with other vaccines were observed aft er tile third dose. Conclusion: HbOC is highly immunogenic in Saudi ch ildren when the vaccine is started at the age of 6 weeks. The use of t he vaccine in the extended program of immunization is expected to conf er protection to a high proportion of Saudi children.