Design of new types of chemical vaccines for the prevention of intestinal infections and problems of their qualitative evaluation. Report 2. Immunochemical characteristics of the experimental preparations]

A study was made of chemical composition and immunochemical properties of 36 samples of the antigenic preparations from typhoid, paratyphoid (A and B) and dysentery (Flexner and Sonne) cultures obtained at the Leningrad, Moscow and Tashkent Institutes of Vaccine and Sera by various methods. The preparations isolated by the method of tryptic proteolysis had a polysaccharide-protein nature, and preparations isolated by the action of chemical reagents (hydroxylamine, hydrogen peroxide, detergents) -- a protein-polysaccharide one. The former contained more nucleic acids, this indicating the presence of components of cytoplasmic and nuclear origin. The preparations were characterized by molecular heterogeneity and contained high- and low-molecular components. The preparations had complex antigenic spectra by the immunodiffusion data; the preparations obtained had complex antigenic spectra by the immunodiffusion data; the preparations obtained had complex antigenic spectra by the immunodiffusion data; the preparations obtained by different method displayed identity reactions, and group specificity was expressed in some of them.     

Comparative study of a diagnostic agent for detecting the antigen of the hepatitis A virus: dried erythrocyte immunoglobulin

The results of the trials of dried erythrocyte immunoglobulin immunodiagnosticum for the detection of hepatitis A virus antigen, developed by a group of scientists at the Tashkent Research Institute for Vaccines and Sera, are presented. The immunodiagnosticum is specific to hepatitis A virus antigen and suitable for the detection of this antigen in fecal and urine samples from patients with viral hepatitis A in the acute stage of the disease.     

Serologic diagnosis of intestinal yersiniosis. The design of a stable erythrocyte preparation for the indirect hemagglutination reaction

Nine types of erythrocyte diagnostica of serovars O3 and O9, differing in the methods of obtaining sensitins and the physical state of erythrocytes, were put on trial. The preparations were used for the titration of hyperimmune sera and blood sera obtained from about 500 healthy persons, 300 patients with Yersinia enteric infection and 300 patients with other diseases. Freeze-dried diagnostica, when compared with liquid ones, were found to be less sensitive, but more stable and specific. Sensitins isolated by the methods of Westphal ad Boivin showed the highest degree of specificity. The authors believe freeze-dried sheep red blood with activated Boivin's antigen adsorbed onto them to be the optimal preparation for use in the passive hemagglutination (PHA) test. The preparation was found to retain its serological activity for as long as 2-3 years. The titer 1:160 (1:200) in the PHA test is recommended as the minimal diagnostic indicator. Erythrocyte diagnosticum is more sensitive, specific and stable than bacterial one. Since 1984 dried Yersinia erythrocyte diagnostica (serovars O3 and O9) have gone into quantity production at the Leningrad Research Institute for Vaccines and Sera.     

Pseudomonas aeruginosa exotoxin

Different P. aeruginosa strains have been found to differ in exotoxin synthesis. The strain isolated at the Mechnikov Research Institute for Vaccines and Sera (Moscow) and newly isolated cultures obtained from patients with the severe course of the infectious process have been found to possess the highest toxigenic activity and to synthesize exotoxins with the most complete set of pathogenically important antigens. The technological scheme for the production of stable exotoxin which can be used for the development of diagnostic, therapeutic and prophylactic preparations against Pseudomonas infections is proposed.     

Isolation and use in virological research of a peroxidase conjugate with protein A

On the basis of proteins A produced at the Mechnikov Central Research Institute for Vaccines and Sera (Moscow) and obtained from Pharmacia AB (Sweden), several batches of peroxidase conjugate have been prepared by a modified method of periodate oxidation. The preparations thus obtained have been evaluated by means of the corresponding enzyme immunoassay systems for the detection of antibodies to herpes simplex and measles viruses. The results of this investigation indicate that serum antibody titers, determined in the assays with antispecific conjugates and with protein A-based based conjugates, coincide. The comparative study of conjugates prepared on the basis of Soviet and imported proteins A has demonstrated their similar activities and specificities.     

The use of monolaurates for removing endotoxins from preparations of cell-free pertussis vaccine]

The possibility of using monolaurates for removing endotoxin from acellular pertussis vaccines developed at the Laboratory of Immunomodulators, Mechnikov Research Institute for Vaccines and Sera (Moscow), has been studied. Monolaurates PEG-400 and PEG-600 obtained, respectively, from Fluka Chemie AG and Ferak GmbH (Germany) have been used. The use of monolaurate PEG-600 ensures the decrease of the toxicity of acellular pertussis vaccines by 2.34-6.3 times.     

Serologic pattern of meningococci in a focus of infection]

The authors present the results of typing of meningococci (isolated from the patients and carriers) by the sera of serological groups A, B, C, D, X, Y, and Z made at the Leningrad Institute of Vaccine and Sera. The causative agents of serological group A were most frequently isolated from the patients with the generalized forms of meningococcus infection. The percentage of detection of meningococci of serological group A was the greatest in the patients and much less in the carriers in and outside the foci of this infection. Many dissociated cultures were revealed among the strains isolated from the carriers. Sera of the Leningrad Institute of Vaccine and Sera have permitted typing of meningococci cultures belonging to various serological groups in accordance with the international classification.     

Assessment of the effectiveness of different methoods of immunization with live plague vaccine EB in aerosol infections]

The work deals with the results of the comparative evaluation of the effectiveness of vaccines developed at the Sanitary Research Institute (Zagorsk) and the Mechnikov Research Institute for Vaccines and Sera (Moscow), as well as two methods of immunization against plague, by inhalation and subcutaneous injection, under the conditions of aerosol infection. The immunogenic effectiveness of both vaccines, when evaluated in terms of LD50, was shown to be approximately the same, but the animals immunized by the inhalation method with the vaccine developed at the Sanitary Research Institute proved to be less susceptible to infection than those immunized with the vaccine developed at the Mechnikov Research Institute for Vaccines and Sera in Moscow. After immunization by the inhalation method the vaccine developed at the Sanitary Research Institute rendered more effective protection (3- to 4-fold) against aerosol infection than after immunization by subcutaneous injection. The animals immunized by the inhalation method proved to be capable of surviving plague in the primary pneumonic form.     

Parathyphoid B-antigen containing a complex of protective surface antigens]

The authors obtained a complex antigen from paratyphoid B bacilli containing complete O-, K- and H-antigens. The preparation was nontoxic and was characterised by marked antigenic properties. In intravenous and oral administration it stimulated production of specific O-, K-, and H-antibodies in high titres. Complex paratyphoid B antigen possessed a marked protective activity and provided intense immunity in subcutaneous and oral administration to experimental animals.     

Laboratory Characteristics of Paratyphoid B Vaccines Tested in Controlled Field Trials

The immunization of human beings with paratyphoid B vaccines, in doses producing a marked protective effect in field trials, resulted in H-agglutinin titers that were significantly higher than those produced by ineffective doses. In immunization of rabbits and white mice, the same difference in doses had a significant effect on the ability of vaccines to stimulate the formation of H and O antibodies. A parallel was noted between the effectiveness of vaccine for human beings and the activity of sera of the corresponding group of people in the passive mouse-protection test, with a correlation between such activity of sera and the 19S O-hemagglutinin titers. The data obtained suggested as promising the determination of agglutinin dynamics in the sera of inoculated human beings and animals to evaluate the antigenic activity of paratyphoid B vaccines in the laboratory. The passive mouse-protection test with human sera holds promise for laboratory evaluation of the effectiveness of paratyphoid B vaccines. At the same time, none of the variation of the active mouse-protection test employed permitted a significant difference to be detected between the vaccines effective and ineffective for man. Comparison of data on the frequency and degree of febrile vaccine reactions in man with results of laboratory evaluation of vaccine toxicity showed that, provided a reference vaccine with known pyrogenic capacity for man was employed, the study of stress effect of vaccines on guinea-pigs (determination of 17-oxycorticosteroid content) may permit prediction of the reactive power of the vaccine. No correlation was found between the pyrogenic capacity of vaccines for man and their toxicity for mice.     

Experimental evaluation of the brucellosis therapeutic vaccine efficacy

Use of antibiotics can't completely solve the problem of brucellosis treatment, especially its chronic forms, because antibacterial preparations do not eliminate main pathogenetic factor of the disease--sensibilization of the macroorganism. It makes actual the question about complex immuno- and antibacterial therapy. Long-term clinical experience proved high effectiveness of a therapeutic brucellosis vaccine. Earlier this preparation was manufactured in Research Institute of Vaccines and Sera in Tbilisi (Georgia). To date new composition of components of the vaccine has been developed, and manufacturing and control methods have been improved. Marked desensitizing effect of the vaccine and its stimulatory action on cellular and humoral immunity has been observed. In 2002 technological normative documentation for manufacturing and use of the vaccine was developed in the Research Institute of Microbiology (Kirov) and production of the vaccine began.     

Polish preparations for preventing and treating infections caused by Pseudomonas aeruginosa

Three preparations, viz. sheep serum for local application ("Sanoserum"), anti-Pseudomonas sheep immunoglobulin for passive immunization ("Immunoglobulin Pseudomonas") and Pseudomonas vaccine for active immunization ("Pseudovac"), have been obtained at the Central Laboratory of Sera and Vaccines in Warsaw, Poland. The laboratory study and clinical trial of these preparations have been carried out. The preparations have proved to be effective as supplement to the conventional methods for the early diagnosis and treatment of P. aeruginosa infection in burn patients.     

Ribosomal dysentery vaccine. III. An immunochemical and serological study]

Sh. sonnei rib oscmes, isolated by differential centrifugation, were previously shown to be highly protect ive against experimental keratoconjunctivitis in guinea pigs. Immunochemical study showed that ribosomal preparations were not uniform in their antigenic composition: as a result of immunoelectrophoretic analysis with the use of anti-ribosomal hyperimmune rabbit antisera, these preparations were found to contain up to 4 antigenic components with different migration rate. The anodic component with the highest elections obtained by the method of Boivin and Grasset and could be inactivated at 60 degrees C or by treatment with trypsin or RNA-se, which suggested its ribonucleoprotein nature. The second thermolabile antigenic component was found to have a moderate anodic mobility and, judging by the results of enzymatic treatment, seemed to be protein. Other antigens with low mobility were resistant to trypsin and RNA-se; one of them, forming a weak precipitation line, could be identified as endotoxin by its antigenic specificity. The use of tanned and ribosome-coated erythrocytes allowed to determine the level of antiribosomal antibodies in the passive hemagglutination test and to evaluate the serological activity of ribosomal preparations in the hemagglutination inhibition test (the minimum inhibiting concentration of ribosomes was 1--2 microgram/ml). The specificity of serological reactions was mainly determined by a highly mobile nucleoproteid component.     

Adsorbed influenza chemical vaccine in the immunization of schoolchildren

When used for the immunization of healthy children aged 7-14 year, adsorbed chemical influenza vaccine produced at the Mechnikov Research Institute for Vaccines and Sera in Ufa has proved to be safe, faintly reactogenic and antigenically very potent. The optimum doses for immunizing children aged 7-10 and 11-14 years have been selected.     

Immunologic study of R-mutants of S. minnesota and water-soluble antigens of S. typhimurium]

Protective properties of Ra- and Re-chemotypes of S. minnesota were studied in experiments on active and passive protection of albino mice from infection with a virulent S. typhimurium culture. Vaccines prepared from the Ra- and Re-mutants of S. minnesota were administered to the animals in the sum total dose of from 0.05 to 0.6 mg. Hyperimmune and normal rabbit sera were administered in doses of 0.3 and 0.5 ml. S. mineesota Ra- and Re-mutants in the doses tested proved to possess a weak protective activity: the level of the immunized mice nonspecific protection from the experimental salmonellosis failed to exceed the natural resistance level. Immunogenicity of Ra-mutant was markedly greater than the immunogenicity of Re-mutant. A marked protective activity against the experimental salmonellosis in mice was possessed by the antigenic complexes from the homologous strain only.     

Possible diagnosis of Pseudomonas aeruginosa infection by an immunoenzyme method using pyoimmunogen as the antigen

The possibility of detecting P. aeruginosa antibodies in patients by means of indirect solid-phase EIA techniques is shown. This assay is carried out with the use of reagents produced in the USSR: polystyrene assay plates manufactured by the Lenigrad Medpolymer Works are used as carriers, P. aeruginosa vaccine (pyoimmunogen) obtained under semi-industrial conditions at the Mechnikov Central Research Institute for Vaccines and Sera is used as antigenic complex and the commercial preparation produced by the Gamaleia Research Institute of Epidemiology and Microbiology serves as conjugate. The studies have revealed that in 95% of cases the level of antibodies in the sera of patients with acute destructive pneumonia accompanied by pleural empyema, abscesses of internal organs and acute hematogenic osteomyelitis is essentially higher than the level of "normal" antibodies in healthy donors from whom biologically confirmed P. aeruginosa cultures can be isolated. In the groups of patients with similar nosological forms of diseases caused by other infective agents such difference in antibody titers is not detected. These results suggest that the detection of antibodies to P. aeruginosa in patients' sera by means of EIA can be used as an additional test for the diagnosis of P. aeruginosa infections.     

Evaluation of the immunogenicity of meningococcal vaccines in experiments on mice]

The immunogenicity of 2 meningococcal vaccines, multicomponent vaccine produced at the Mechnikov Research Institute for Vaccines and Sera in Moscow and polysaccharide vaccine obtained from Merck Sharp & Dohme (USA), was evaluated on experimental meningococcal sepsis in mice, produced by the injection of meningococcal culture in mucin suspension. The protective effect of these 2 vaccines, expressed in terms of ED50, was 0.28 +/- 0.12 for the multicomponent vaccine and 0.25 +/- 0.24 for the polysaccharide vaccine; the challenge dose used in the test was 10 LD50 of the culture. The multicomponent vaccine gave the maximum immunological effect in a dose of 8 micrograms, while higher or lower doses induced a lesser increase in antibody titer and thus gave lower protection to mice against infection.     

The reactogenicity and efficacy of a dried cell-free staphylococcal vaccine in treating chronic bronchitis]

The data obtained in the controlled trial of the immunotherapy of chronic bronchitis (CB) patients with lyophilized acellular staphylococcal vaccine developed at the Mechnikov Research Institute for Vaccines and Sera (USSR Acad. Med. Sci.), Moscow, are presented. The patients were divided at random into two groups; of these, one group received the vaccine and the other, placebo (0.9% sodium chloride solution). The preparations were injected subcutaneously simultaneously with traditional treatment. The vaccine was well tolerated by the patients. In the blood of the patients receiving the vaccine, in contrast to those receiving placebo, a significant increase in the level of specific antibodies determined in the passive hemagglutination test and IgG was noted. When following the remote consequences of the disease for a year after the course of immunotherapy, a significant decrease in the occurrence of aggravations, an increase in the duration of remission and a decrease in the duration of sick leaves were registered. These data indicate that the immunotherapy of CB with lyophilized acellular staphylococcal vaccine is a promising method of preventing relapses.     

Experimental study of vaccines against Salmonella typhimurium infection.

Serological and protective activities of vaccines from S. typhimurium and S. minnesota were studied. It has been demonstrated that active protection against infection in experimental salmonellosis in mice can only be obtained by immunization of the animals using vaccines from complete antigenic complexes isolated from S-strains. It has been found that expressed anti-infection immunity (unlike anti-endotoxic immunity) is induced to the same extent by either high-molecular components (2,000,000 daltons and more), showing great serological activity, or components with relatively low molecular weight (15,000--20,000 daltons) and minimum serological activity. Vaccines from Ra- and Re-strains of S. minnesota do not induce resistance to S. typhimurium infection in mice in either active protection tests or passive protection tests.     

Morphological alterations in animal organs after the injection of acellular pertussis vaccine with immunomodulator

Toxic properties of acellular pertussis vaccine (APV) and morphological changes in white mice in response to intramuscular injection of APV (without or with immunomodulator glucosaminylmuramyl dipeptide-GMDP) were under study. APV used in these experiments was developed at the Mechnikov Research Institute for Vaccines and Sera (the Russian Acad. Med. Sci.) on the basis of Bordetella pertussis cultures in synthetic fluid culture media. In experiments on acute and chronic toxicity of APV (without GMDP) increased tissue immunity reactions in spleen, thymus, liver, lungs and intestinal wall was detected. There was no difference in immunomorphological reactions in mice receiving APV with different doses of GMDP, but some difference was observed in time dynamics of tissue immunity reactions. A small dose of GMDP should be preferred (0.0001 microgram) which results in gradual growth of tissue immunity reactions less pronounced toxic reactions caused be the APV injection.