Optimization of casein-based semisynthetic medium for growing of toxigenicCorinebacterium diphtheriaein a fermenter

Heterologous Expression of Recombinant Proteins and Their Derivatives Used as Carriers for Conjugate Vaccines

Carrier proteins that provide an effective and long-term immune response to weak antigens has become a real breakthrough in the disease prevention, making it available to a wider range of patients and making it possible to obtain reliable vaccines against a variety of pathogens. Currently, research is continuing both to identify new peptides, proteins, and their complexes potentially suitable for use as carriers, and to develop new methods for isolation, purification, and conjugation of already known and well-established proteins. The use of recombinant proteins has a number of advantages over isolation from natural sources, such as simpler cultivation of the host organism, the possibility of modifying genetic constructs, use of numerous promoter variants, signal sequences, and other regulatory elements. This review is devoted to the methods of obtaining both traditional and new recombinant proteins and their derivatives already being used or potentially suitable for use as carrier proteins in conjugate vaccines.

A phase III, randomized controlled study to assess the safety and immunogenicity of a semi-synthetic diphtheria, tetanus and whole-cell pertussis vaccine in Indian infants

BACKGROUND

Reactions to DTwP vaccine are well known and are a matter of great concern, much for the development of next generation combination vaccines. To avoid such reactions which occur from foreign compounds, WHO suggested manufacture of DTwP vaccine using semi-synthetic medium. The phase III trial reported here was conducted to assess the immunogenicity, tolerability and safety of a new DTwP vaccine manufactured using semi-synthetic medium for both tetanus and diphtheria toxoids in comparison with the routinely manufactured DTwP vaccine.

METHODS

In all, 331 infants aged 6-8 weeks were enrolled, out of which 308 completed the study. The vaccination was done at 6-10-14 weeks following EPI/WHO recommended immunization schedule. Blood samples were collected prior to the administration of first dose and one month after the third dose.

RESULTS

Postvaccination, geometric mean titres for each component did not differ significantly amongst the two study groups. Though, the immunogenicity results were comparable between the two vaccines, the incidence of adverse events was comparatively low in semi-synthetic vaccine as against the routine vaccine group for all the three doses.

CONCLUSIONS

The semi-synthetic DTwP vaccine was immunogenic and showed a significant lower incidence of local adverse events in comparison to the routine vaccine. This vaccine is now being used in the routine vaccination programme both as a triple antigen (DTwP alone) as well as a combination with Hepatitis B and/or Haemophilus influenzae type b vaccine.

Two Japanese Corynebacterium ulcerans isolates from the same hospital: ribotype, toxigenicity and serum antitoxin titre

Two toxigenic Corynebacterium ulcerans isolates recovered from pharyngeal swabs of two patients from the same hospital in Japan during 2001–2002 were characterized by PFGE and ribotyping. Toxin production in different culture media was examined and serological analysis of patient sera was performed. The two isolates could not be distinguished by PFGE; however, their ribotypes were distinguishable. One of the isolates could represent a novel ribotype. Analysis of toxin production in different culture media demonstrated that the two isolates produced varying amounts of the diphtheria toxin. Serological analysis showed a greater than sevenfold increase in the serum antitoxin titre during the course of infection in one patient.