Fully liquid DTaP-IPV-Hib pediatric combination vaccine (Pediacel): a review of 18 years of clinical experience

Surveillance on the adverse events following immunization with the pentavalent vaccine in Zhejiang, China

Objectives

The aim of this study is to describe the reporting rate of adverse events following immunization (AEFI) with pentavalent vaccine: diphtheria-pertussis-tetanus-poliomyelitis-Haemophilus influenzae type b (DPT-IPV/Hib), and to determine whether the reporting rate of AEFI following DPT-IPV/Hib was higher than the average level of the other vaccines.

Methods

Review and describe the AEFI reported to national adverse event following immunization surveillance system (NAEFISS) in Zhejiang province from 2015 to 2020. Reporting rates of AEFI were calculated by age, city, severity of AEFI, categories of AEFI, and reaction categories. The data mining algorithm used in this study was reporting odds ratio (ROR). A value of ROR‑1.96SE >1 (standard error [SE]) was considered as positive signal.

Results

NAEFISS received 5726 AEFI reports following DTP-IPV/Hib, with a reporting rate of 20.01/10000 doses. Of the reported AEFI, 202 were serious vaccine product-related reactions, including two cases of anaphylactic shock, five cases of Guillain Barre Syndrome (GBS) and two cases of acute disseminated encephalomyelitis. The reporting rate of fever/redness/induration was the highest among all the clinical diagnosis (14.97/10000 doses). The positive signals were obtained for allergic rash (ROR-1.96SE: 1.36), febrile convulsion (ROR-1.96SE: 1.32) and GBS (ROR-1.96SE: 1.16).

Conclusion

The present findings bolstered that the DTP-IPV/Hib administered as the four-dose schedule was generally well tolerated in Chinese infants as we did not identify any new/unexpected safety concern from the NAEFISS during a six-year timespan.

Glycoconjugate Vaccines for Prevention of Haemophilus influenzae Type b Diseases

This review summarizes the experience in laboratory- and industrial-scale syntheses of glycoconjugate vaccines used for prevention of infectious diseases caused by Haemophilus influenzae type b bacteria based on the linear capsular polysaccharide poly-3-β-D-ribosyl-(1→1)-D-ribitol-5-phosphate (PRP) or related synthetic oligosaccharide ligands. The methods for preparation of related oligosaccharide derivatives and results of the studies evaluating effect of their length on immunogenic properties of the conjugates with protein carriers are overviewed.

Peptides, Antibodies, Peptide Antibodies and More

The applications of peptides and antibodies to multiple targets have emerged as powerful tools in research, diagnostics, vaccine development, and therapeutics. Antibodies are unique since they, in theory, can be directed to any desired target, which illustrates their versatile nature and broad spectrum of use as illustrated by numerous applications of peptide antibodies. In recent years, due to the inherent limitations such as size and physical properties of antibodies, it has been attempted to generate new molecular compounds with equally high specificity and affinity, albeit with relatively low success. Based on this, peptides, antibodies, and peptide antibodies have established their importance and remain crucial reagents in molecular biology.

Hib antibody responses in infants following diphtheria, tetanus, acellular pertussis, and conjugated Haemophilus influenzae type b (Hib) combination vaccines with decreasing amounts of tetanus toxoid

BACKGROUND

While combination vaccines have contributed to improved vaccine uptake rates in children, studies have documented varied immunogenicity to specific vaccine components. We studied whether varying the amount of tetanus toxoid (TT) in a DTaP and Hib combination vaccine would result in immunogenicity comparable with separate, concurrent administration.

METHODS

We evaluated the immunogenicity of Massachusetts Biologic Laboratories (MBL) diphtheria, tetanus, and acellular pertussis (mDTaP) vaccine combined with tetanus-conjugated MBL Haemophilus influenzae type b vaccine (mHib) in a single injection (DTaPH). We compared four DTaPH vaccines containing varying concentrations of TT. We also evaluated the immune response to the DTaP vaccine manufactured by Connaught Laboratories (now known as Sanofi Pasteur) given with mHib and with Wyeth Hib-CRM₁₉₇ (HbOC) as separate injections. Vaccines were administered to 240 healthy infants at 2, 4, and 6 months of age, and blood specimens for antibody determination were obtained before each immunization and one month after the third immunization.

RESULTS

We found no significant differences in immune response to the vaccines between the four DTaPH groups. Hib antibody responses were similar in the mHib and the HbOC groups but significantly lower in the DTaPH groups, as measured by Chinese Hamster Ovary (CHO) cell neutralization titers and filamentous hemagglutinin antigen (FHA) geometric mean concentrations (GMC) of anti-Hib antibodies. There were no significant differences between the groups in pertussis or tetanus toxoid antibody levels.

CONCLUSION

Reducing tetanus toxoid amounts did not produce comparable immunogenicity for Hib. The nature of the interaction between immune responses to DTaPH components should be explored further to enable the development of better Hib-containing combination vaccines.