ABSTRACT
With the development and widespread use of diphtheria-tetanus-pertussis (DTP)-based combined vaccines, the number of vaccinations and the cost of vaccination implementation have gradually decreased, which has a positive and profound impact on implementing immunization programmes and meeting differentiated needs. The development of formulation process is critical to the research on combined vaccines, and a formulation process with good robustness and flexibility plays a vital role in vaccine immunogenicity, antigen compatibility and product stability. This article discussed some common issues in the chemical manufacture and control (CMC) of DTP-based combined vaccines referring to the regulatory consensus of various countries and related organizations.
ABSTRACT
Pertussis toxin (PT) is one of the major virulence factors of Borrelia pertussis and also an essential component of pertussis vaccines. Before using it in vaccine production, detoxification is necessa-ry because of its biological activity. This paper summarized the structure and detoxification process of PT as well as the safety and immunogenicity of pertussis vaccines prepared with detoxified PT.
ABSTRACT
Objective To evaluate the immunogenicity of the recombinant human papillomavirus type 68b (HPV68b) virus-like particles(VLPs)in a mouse model.Methods The L1 protein of HPV type 68b was successful expressed in the Hansenula polymorpha strain (NVSI-68b-1).Processes including purifi-cation and reconstitution were performed to achieve pure HPV 68b VLPs.The purity, morphology and immu-nogenicity of the purified HPV 68 b VLPs were further analyzed .The BALB/c mice were immunized with HPV68b VLPs formulated on aluminum adjuvant .Pseudovirus-neutralizing antibody ( PsV NAb) assay was performed to detect the neutralizing antibodies in serum samples .Results The HPV 68 b L1 VLPs were ob-tained as indicated by the results of SDS-PAGE, Western blot assay , HPLC, electron microscopy and dy-namic light scattering with a high purity of 95%.Transmission electron microscopy and dynamic light scat-tering analysis revealed that the HPV68b L1 VLPs resembled the native virus with an average particle diame-ter of 50 nm.High levels of HPV68b-neutralizing antibodies were detected in serum samples from the mice immunized with HPV68b L1 VLPs.Moreover, a cross-protective efficacy of HPV68b L1 VLPs for HPV68a was observed .Conclusion This study suggested that the recombinant HPV 68 b VLPs expressed in a Han-senula polymorpha strain might be used as a potential candidate for the development of HPV vaccine .