The evaluation of the reactogenicity and immunogenic activity of a new concentrated inactivated leptospirosis vaccine

In the controlled field trial the reactogenicity, safety and antigenic activity of a new concentrated inactivated leptospirosis vaccine after its administration in one and two injections of 0.5 ml were studied in comparison with those of the existing commercial vaccine, introduced in two injections in doses of 2.0 and 2.5 ml. The new experimental vaccine exhibited low reactogenicity and was found to be safe and highly immunogenic when introduced in a single injection of 0.5 ml. As shown in this trial, the immunogenic characteristics of immunization made in a single injection were not inferior than those obtained as the result of immunization made in two injections, yielding high percentage of seroconversions (89.8% to 98.3%) with respect to 4 Leptospira serogroups and leading to the production of the protective titers of corresponding antibodies. The existing commercial vaccine was inferior to the experimental one in antigenic activity (the frequency of seroconversions, antibody titers). The results of the trial make it possible to recommend the experimental concentrated leptospirosis vaccine for use in medical practice in a dose of 0.5 ml introduced in a single injection.     

Immunological activity of a Proteus vaccine administered to volunteers simultaneously with a pyoimmunogen and adsorbed staphylococcal anatoxin

The comparative study of the immunological activity of Proteus vaccine prepared from soluble antigenic complexes was made after the immunization of volunteers with this vaccine used in the form of a single preparation and in combination with pyoimmunogen (Pseudomonas aeruginosa vaccine) and/or adsorbed staphylococcal toxoid. The injection of the vaccine in the form of a single preparation and in different combinations increased the ingestion of Proteus cells by neutrophils. The injection of Proteus vaccine simultaneously with pyoimmunogen and staphylococcal toxoid ensured the intensive phagocytosis of staphylococci. All combinations with Proteus vaccine, used in this investigation, stimulated the intensive formation of antibodies to Proteus vaccine strain and Re-glycolipid. Proteus vaccine introduced in combination with adsorbed staphylococcal toxoid essentially stimulated the synthesis of anti-alpha-staphylolysin.     

Immunomorphologic aspects of local (wound) revaccination with tetanus anatoxin

The immunomorphological reaction of regional lymphoid organs, the pathomorphology of wound tissues, humoral antitoxic response and a protective effect after local (wound) booster immunization with tetanus toxoid have been studied in observations on 100 guinea pigs with experimental wound infection. The study has shown that the local application of tetanus toxoid, besides stimulating humoral response, induces a more rapid effect aimed at the primary elements of the infectious process (the germination of spores, the adhesion, colonization and toxin formation of the causative agent), thus facilitating the localization of the focus of infection, the development of reparative processes in the wound and the arresting of the infection.     

Reactogenicity and antigenic activity of a chromatographic cultured purified and concentrated inactivated dried vaccine against tick-borne encephalitis

The study of the characteristics of a new dried tissue-culture purified concentrated inactivated vaccine against tick-borne encephalitis, manufactured in the USSR, has revealed that the preparation is moderately reactogenic and produces no definite side effects in the vaccinees. In the process of the controlled epidemiological trial the optimum vaccination schedule for the primary immunization of adults against tick-borne encephalitis with the new preparation has been determined by the study of serum samples from the vaccinees in the hemagglutination inhibition test and the neutralization test in tissue culture. In accordance with this vaccination schedule the course of primary immunization with the chromatographic variant of the concentrated vaccine consists of two injections in a dose of 0.5 ml, made at an interval of 6 months.     

Stimulation of cynomolgus peripheral blood lymphocytes with tetanus toxoid and smallpox vaccine

The cynomolgus monkey was studied as an animal model to investigate the cell-mediated immunity induced by vaccines. Optimal conditions are described to isolate peripheral blood lymphocytes. Lymphocyte transformation tests were performed with tetanus toxoid and smallpox vaccine. Antigen-specific lymphocyte transformations with smallpox vaccine could only be demonstrated when lymphocytes were obtained from vaccinated monkeys. Tetanus toxoid appeared to be a weak antigen. However, after adsorption of the toxoid to aluminum phosphate, a significant antigen-specific lymphocyte transformation was observed.     

Antigen-specific and antigen-nonspecific reactions of the immunity system in vaccination with a purified concentrated staphylococcal anatoxin

Immunization with purified and concentrated staphylococcal toxoid leads to the rapid 12-fold rise of the level of anti-alpha-toxin and to the 17-fold rise of the titres of antibodies to extracellular staphylococcal products. At the period of immunization phasic changes in cell-mediated and humoral immunity characteristics, indicative of the state of the nonspecific resistance system, can be observed. These changes consist in the transient suppression of phagocytosis, including a decrease in the activity of intraleukocytic bactericidal systems (myeloperoxidase and cation protein), a decrease in the activity of the complement and the bactericidal activity of the blood serum, which should be taken into account when using this immune preparation for therapy.     

The capacity of purified staphylococcal anatoxin to correct antigen-specific and antigen-nonspecific immunological defects]

Purified staphylococcal toxoid is capable of partially preventing the development of antigen-specific (induced by the supraoptimal dose of sheep red blood cells) and antigen-nonspecific (induced by Tahyna virus) defects of humoral immune response, as well as abolishing these defects. The presence and manifestation of the correction of virus-induced immunodeficiency is determined by the dose of the toxoid and the interval between the injections of purified staphylococcal toxoid and the infective agent.     

Preparation of a purified, inactivated Japanese encephalitis (JE) virus vaccine in Vero cells

An attenuated Japanese encephalitis (JE) virus SA14-14-2 (PDK) was adapted to Vero cells, a continuous cell line that has been licensed for human vaccine production, by serial passages. The resulting virus was purified by tangential flow ultrafiltration followed by sucrose density gradient ultracentrifugation, giving 2.3 mg purified virus per liter of culture supernatant. Treatment with 0.05% formalin for 4 days at 22 °C completely inactivated viral infectivity while preserving its antigenicity. The purified, inactivated JE virus was formulated with alum hydroxide and administered to mice by intraperitoneal route. In terms of its ability to induce anti-JE neutralizing antibody and to protect the immunized animal against neurovirulent virus challenge, the purified, inactivated JE virus formulated with alum was equivalent to the exiting commercial mouse brain-derived vaccine (JE-VAX, Aventis Pasteur Inc.).     

Memory and cellular immunity induced by a DNA vaccine encoding self antigen TPD52 administered with soluble GM-CSF

Tumor protein D52 (TPD52) is involved in cellular transformation, proliferation and metastasis. TPD52 over expression has been demonstrated in several cancers including prostate, breast, and ovarian carcinomas. Murine TPD52 (mD52) has been shown to induce anchorage independent growth in vitro and metastasis in vivo, and mirrors the function and normal tissue expression patterns of the human orthologue of TPD52. We believe TPD52 represents a self, non-mutated tumor associated antigen (TAA) important for maintaining a transformed and metastatic cellular phenotype. The transgenic adeno-carcinoma of the mouse prostate (TRAMP) model was employed to study mD52 as a vaccine antigen. Naïve mice were immunized with either recombinant mD52 protein or plasmid DNA encoding the full-length cDNA of mD52. Following immunization, mice were challenged with a subcutaneous, tumorigenic dose of mD52 positive, autochthonous TRAMP-C1 tumor cells. Sixty percent of mice were tumor free 85 days post challenge with TRAMP-C1 when immunized with mD52 as a DNA-based vaccine admixed with soluble granulocyte-macrophage colony stimulating factor (GM-CSF). Survivors of the initial tumor challenge rejected a second tumor challenge given in the opposite flank approximately 150 days after the first challenge, and remained tumor free for more than an additional 100 days. The T cell cytokine secretion patterns from tumor challenge survivors indicated that a T_H1-type cellular immune response was involved in tumor protection. These data suggest that mD52 vaccination induced a memory, cellular immune response that resulted in protection from murine prostate tumors that naturally over express mD52 protein.     

Biological and immunogenic characteristics of Chlamydia trachomatis strain MT-2A (serovar D) and its use for development of experimental inactivated vaccine

Biological characteristics of C. trachomatis author's strain MT-2A (serovar D) is presented. Stages of development on its basis the experimental formalin-inactivated vaccine against Chlamydia were described. Humoral and cellular immune response to the vaccine administered on 3-dose immunization schedule in conjunction with polyoxidonium as adjuvant was studied. Significant immunological efficacy of the vaccine was shown. T- and B-cell immune responses were characterized. Titer of IgG antibodies against Chlamydia in blood serum after 3rd dose of the vaccine was 10,880+/-1,817.76. Assessment of T-cell response showed that reaction of delayed hypersensitivity with formation of granuloma presented in 60% of animals. Proportion of immunoblasts in reaction of blast-transformation was 29.3+/-2.8%. Perspectives of further studies of the developed corpuscular vaccine against Chlamydia are discussed.