Child ; Child, Preschool ; China ; epidemiology ; Haemophilus Infections ; epidemiology ; immunology ; microbiology ; prevention & control ; Haemophilus influenzae type b ; immunology ; Humans ; Vaccination

Diphtheria-Tetanus-acellular Pertussis Vaccines ; Haemophilus influenzae type b ; immunology ; Influenza Vaccines ; Vaccination ; methods ; Vaccines, Combined

The incidence of invasive diseases, including meningitis caused by Haemophilus influenzae type b (Hib) was markedly decreased after routine immunization of Hib vaccine through diverse schedules in many countries. The purpose of this study was to evaluate the immunogenicity and safety of Hib conjugate vaccines in Korean children before the implementation of a national immunization program against Hib in Korea. A multicenter controlled trial was performed on two different Hib vaccines in Korean children. A total of 319 infants were enrolled: 199 infants were immunized with the Hib polysaccharide conjugated to the tetanus toxoid (PRP-T) and 120 infants with the Hib polysaccharide conjugated to the outer-membrane protein of Neisseria meningitides (PRP-OMP). Immunogenicity was evaluated by enzyme-linked immunosorbent assay (ELISA) and serum bactericidal assay. Both vaccines showed good immunologic responses after primary immunization. After 2 doses of PRP-T or PRP-OMP, 78.9% and 91.7% of infants achieved an antibody level of > or = 1.0 microgram/mL, respectively. Both vaccines were safe and well-tolerated. No serious adverse events were observed. Thus, Hib conjugate vaccines appear to be safe and show good immunogenicity in Korean infants. These results will be important reference data for the implementation of Hib vaccine in the national immunization program of Korea.
Bacterial Outer Membrane Proteins/administration & dosage/*adverse ; Enzyme-Linked Immunosorbent Assay ; Haemophilus Vaccines/administration & dosage/*adverse effects/*immunology ; Haemophilus influenzae type b/*immunology ; Humans ; Infant ; Korea ; Polysaccharides, Bacterial/administration & dosage/*adverse effects/*immunology ; Tetanus Toxoid/administration & dosage/*adverse effects/*immunology

INTRODUCTIONIn recent years, acellular pertussis combination vaccines have facilitated compliance with and coverage of the national immunisation programme in Singapore. This phase-II study (Rota-007) evaluated the immunogenicity, reactogenicity and safety of a DTPa-IPV/Hib combined vaccine when co-administered with a rotavirus vaccine.

MATERIALS AND METHODSA total of 2464 children aged 3 months were vaccinated with DTPa-IPV/Hib together with a randomised 1:3 ratio of either placebo (n=653) or 1 of 3 different formulations of a rotavirus vaccine. Blood samples were collected for immunogenicity analysis 1 month after the third DTPa-IPV/Hib vaccine dose in a subset of subjects (n = 640). Local and general reactogenicity and unsolicited adverse events were recorded during the follow-up after each vaccination.

RESULTSSerological analysis showed >95% response for all antigens in the co-administered DTPa-IPV/Hib vaccine, with no difference between the rotavirus vaccine and placebo groups. No differences in adverse events and reactogenicity were reported in the rotavirus vaccine and placebo groups. Only 0.2% of the subjects reported Grade 3 adverse events. Three subjects (from the vaccine groups) died during the study, which were assessed by the investigators as unrelated to vaccination. No deaths were reported in the placebo group.

CONCLUSIONThe combined DTPa- IPV/Hib vaccine is safe, well tolerated and highly immunogenic when given alone or coadministered with the rotavirus vaccine for infants in Singapore.

Child ; Child Welfare ; Child, Preschool ; Double-Blind Method ; Female ; Haemophilus Infections ; immunology ; prevention & control ; Haemophilus influenzae type b ; isolation & purification ; Humans ; Infant ; Infant, Newborn ; Male ; Patient Compliance ; Poliomyelitis ; prevention & control ; Rotavirus Vaccines ; Singapore ; Vaccines, Combined ; Vaccines, Conjugate ; adverse effects ; immunology

The purpose of our experiment is to examine the level of anti-Haemophilus influenza polysaccharide antibody titer in the Korean population. Using ELISA, the level of Hib-PS antibodies in 384 infants and children who were all free from Hib invasive diseases, was tested. And the blood of 50 mothers within 24 hours of delivery and cord blood from their respective full-term neonates was also tested. The transport of Hib-PS IgG and IgG subclasses in paired sera from mothers and neonates was also measured. The titer of Hib-PS IgG varies with age. At birth the mean optical density of cord blood was 1.028; however, it declined to 0.609 up to 6 months and further decline was noted up to 2 years to 0.488. Then the mean O.D. remained around 0.5 from 3 to 14 years of age. The mean O.D. of Hib-PS IgG in the mothers blood was 0.856. The ratio of mean O.D. of anti-Hib PS IgG antibody in the cord blood to that in the maternal blood was 1.20. The mean optical densities of IgG subclasses were: 1.18 for anti-Hib PS IgG1, 1.07 for anti-Hib PS IgG2, 1.01 for anti-Hib PS IgG3, and 1.09 for anti-Hib PS IgG4. The sera from Korean children of almost all age groups reacted to Hib-PS antigen on ELISA. Also the active transport of anti-Hib PS IgG antibody through placenta was observed. Among four IgG subclasses, only IgG1 transport had significant experimental meaning.
Adolescent ; Adult ; Antibodies, Bacterial/*immunology ; Antigens, Bacterial/*immunology ; Bacterial Capsules ; Child ; Child, Preschool ; Enzyme-Linked Immunosorbent Assay ; Female ; Fetal Blood/immunology ; Haemophilus Vaccines/*immunology ; Haemophilus influenzae/*immunology ; Humans ; Immunoglobulin G/classification/immunology ; Infant ; Infant, Newborn ; Korea ; Male ; Maternal-Fetal Exchange ; Polysaccharides, Bacterial/*immunology ; Pregnancy

OBJECTIVETo express and purify Hap protein of nontypeable Haemophilus influenzae (NTHi) in prokaryotic system, and study its immunogenicity and adhesive activity.

METHODHap protein was expressed in E.coli BL21 with pET32a (+)-Hap and purified by affinity chromatography. The adhesive activity of the recombinant Hap protein was observed in competitive adhesion assay using scanning electron microscope and bacterial counting. BALB/C mice were immunized intranasally with the purified recombinant Hap protein and cholera toxin B subunit (CT-B), and anti-Hap IgA and IgG were detected by enzyme-linked immunosorbent assay.

RESULTSSDS-PAGE analysis showed a single band of the target protein, whose purity reached 85% according to the result of Gel analysis software. The concentration of the protein was 3.2 g/L after ultrafiltration and condensation. Competitive adhesion assay showed that compared with control group, the recombinant Hap protein significantly inhibited the adhesion of NTHi to ECM (P<0.01). Compared with Hap immunization alone, immunization with Hap combined with CT-B resulted in significantly higher titers of anti-Hap IgG and IgA in mice (P<0.05).

CONCLUSIONHighly purified recombinant Hap protein has been obtained in a prokaryotic system and shows good immunogenic and adhesive activities. These results will establish the basis for further study of NTHi vaccine.

Adhesiveness ; Animals ; Bacterial Outer Membrane Proteins ; biosynthesis ; genetics ; immunology ; Cholera Toxin ; immunology ; Escherichia coli ; genetics ; metabolism ; Haemophilus Infections ; prevention & control ; Haemophilus influenzae ; metabolism ; Immunization ; Immunoglobulin A ; blood ; Immunoglobulin G ; blood ; Mice ; Mice, Inbred BALB C ; Recombinant Proteins ; biosynthesis ; genetics ; immunology ; Serine Endopeptidases ; biosynthesis ; genetics ; immunology

INTRODUCTIONChildren in Singapore receive vaccination against hepatitis B virus (HBV) at 0, 1 and 5 or 6 months of age, and vaccination against pertussis, diphtheria, tetanus, and polio at 3, 4 and 5 months of age. Parents often choose to vaccinate with the combined acellular-pertussis-inactivated polio-Hib vaccine (DTPa-IPV/Hib). We investigated whether a combined hexavalent vaccine, DTPa-HBV-IPV/Hib, could replace the separate administration of DTPa-IPV/Hib and HBV for the final vaccination at 5 months of age (Trial DTPa-HBV-IPV-075).

MATERIALS AND METHODSIn an open study, 150 children were randomised to complete their vaccination schedule with DTPa-IPV/Hib + HBV or DTPa-HBV-IPV/Hib.

RESULTSOne month after the final vaccination, there was no difference between groups in seroprotection rates or antibody concentrations against HBV. Seroprotection rates against diphtheria, tetanus, Hib and polio, as well as vaccine response rates to pertussis antigens were also similar between groups. Local and general symptoms occurred at a similar rate after the third dose of either vaccine.

CONCLUSIONThe immunogenicity and reactogenicity of the hexavalent vaccine DTPa-HBV-IPV/Hib (Infanrix hexa, GSK) group is comparable to that of separately administered DTPa-IPV/Hib and HBV vaccines. Combined hexavalent vaccine, DTPa-HBV-IPV/Hib, could replace the separate administration of DTPa-IPV/Hib and HBV for vaccination at 5 months of age, thereby reducing the number of injections required.

Diphtheria ; immunology ; Diphtheria-Tetanus-Pertussis Vaccine ; Female ; Haemophilus Vaccines ; Haemophilus influenzae ; immunology ; Hepatitis B ; prevention & control ; Hepatitis B Antibodies ; blood ; Hepatitis B Vaccines ; administration & dosage ; Humans ; Immunization Schedule ; Infant ; Infant, Newborn ; Male ; Poliovirus Vaccine, Inactivated ; Singapore ; Tetanus ; immunology ; Vaccination ; Vaccines, Combined ; administration & dosage ; Vaccines, Inactivated