METHODS FOR ASSESSMENT OF THE SPECIFIC ACTIVITY OF DRUGS FOR PREVENTION OF HEPATITIS B.

The immunologic activity (specific activity) is one of the main indicators of quality of vaccines for prophylaxis of hepatitis B, along with their safety. Retrospective analysis of the use of laboratory methods for assessment of specific (immunogenic) activity of modern vaccines against hepatitis B using indicators was carried out: in vitro method based on evaluation of HBsAg content and in vivo method based on evaluation of immunogenic activity in mice. Both methods are standardized and described in normative documents on the vaccines against hepatitis B of domestic production registered in the Russian Federation.

[Vitaherpavac is the first Russian herpes simplex virus vaccine obtained on the Vero B continuous cell line].

Vitaherpavac, a dry inactivated herpes simplex virus (HSV) culture vaccine, has been obtained, by using the Vero B continuous cell line as a substrate for accumulation of herpes simplex virus types 1 (US strain) and 2 (VN strain). Vitaherpavac and the similar vaccine Herpovax made by the Research Institute of Vaccines and Sera, Saint Petersburg (for which preparation a primary trypsinized chick embryo cell culture used as a substrate for accumulation of HSV types 1 and 2), underwent comparative clinical trials. The tolerability and therapeutic effectiveness of the vaccine were tested in patients diagnosed as having chronic frequently recurring herpes.

[Diagnostic advantages of the test system "DS-EIA-HBsAg-0.01" for detection of HBV surface antigen].

The new highly sensitive test system "DS-EIA-HBsAg-0.01" (Priority Certificate No. 2006129019 of August 10, 2006) in detecting hepatitis B surface antigen (HBsAg) was assessed.

[The evaluation of the diagnostic value of PCR test systems according to the results of state trials].

The method for the diagnostic value evaluation of preparations, based on the calculation of the accuracy of test results and taking into account the spread of the diagnosed disease (the comparison of the PCR test systems for the diagnostics of hepatitis B and ureaplasmosis) is proposed. As shown in this work, evaluations obtained with the use of this method coincide with those obtained on the basis of prognostic value, but are more convenient in use and provide additional information.

[Evaluation of the reactogenicity and immunogenic potency of combined vaccine "Bubo-Kok" in the immunization of children against diphtheria, tetanus, pertussis and viral hepatitis B].

Combined vaccine "Bubo-Kok" is characterized by safety and high immunological activity. The number of postvaccinal reactions in children aged 1 and 2 years, immunized with vaccine "Bubo-Kok", was not statistically different from those in groups of children immunized with adsorbed DPT vaccine, as well with such vaccine in combination with vaccine against hepatitis B. After the completion of the primary course of immunization 100% of children had protective antibody titers against diphtheria, tetanus and hepatitis B.

Limits of diagnostic accuracy of anti-hepatitis C virus antibodies detection by ELISA and immunoblot assay.

When human sera samples are tested for anti-hepatitis C virus (HCV) antibodies using different ELISA kits as well as immunoblot assay kits discrepant results often occur. As a result the diagnostics of HCV infection in such sera remains unclear. The purpose of this investigation is to define the limits of HCV serodiagnostics.

[Stability of hepatitis C virus RNA in human blood plasma in a panel of control samples].

The stability of hepatitis C virus (HPC) RNA concentration in 5 human plasma samples after storage at +22 degrees C for two months, at -20 degrees C, and +4 degrees C for six months after 10 freezing-unfreezing cycles was evaluated. In this study, the concentration of HCV RNA in the samples was stable after six months of storage at -20 degrees C. The concentration of HCV RNA decreased on the average of 92% after 2-month storage at +22 degrees C.

[Evaluation of the diagnostic efficacy of a test system for detecting hepatitis virus C RNA by polymerase chain reaction "AmpliSens(TM) HCV-240/BKO-440)"].

The test system developed at the Central Research Institute of Epidemiology, Ministry of Health of the Russian Federation for identification of hepatitis C virus RNA was studied. The sensitivity of the test system which the rate of similar results was 100% with its 5-fold reproduction was evaluated. That was 5 x 103 genomic equivalents (or international units) per ml of a sample.

[Reactions to and immunogenic properties of the combined vaccine Bubo-M for immunization of children against diphtheria, tetanus and viral hepatitis B].

Bubo-M, the first Russian combined vaccine, was found to have low reactogenicity. The difference between the number of postvaccinal reactions in the group of children immunized with Bubo-M (25.9%) and those in the group of children who had been simultaneously injected into different sites of the body with ADS-M toxoid (adsorbed DT toxoid with reduced antigen content) and hepatitis B vaccine (26.

[Evaluation of reactogenicity and immunogenicity of Bubo-M, the Russian combined vaccine for immunization of adults against diphtheria, tetanus and viral hepatitis B].

Bubo-M, the first Russian associated vaccine, was found to have low reactogenicity and high immunogenic potency. The frequency of postvaccinal reactions in the group of persons immunized with Bubo-M (20%) appeared to be considerably lower than among persons who received the combined injection of adsorbed DT toxoid with reduced antigen content and vaccine against hepatitis B (47.7%).

[Construction of reference panel of immune serum against hepatitis C virus with standard level of IgG antibodies].

A panel of anti-HCV sera (lot 03HC) was prepared from human sera obtained at blood transfusion centers and infectious hospitals. Donor sera and high-titer sera from patients infected with HCV were used. For positive samples, specific sera reactive with the core and/or NS proteins of HCV 1b and 2 were selected.

[Development of sera reference panels for quality control of ELISA diagnostic kits in Russia].

In the past 5 years, the investigators of the "VECTOR" SRB VB and the L.A. Tarasevich State Institute of Standardization and Control of Medical Biological Preparations have jointly designed sera reference panels containing anti-HIV-1 IgG, anti-HCV IgG, and anti-HAV IgM which have been approved as national standard panels.

[The use of Vero (B) cell line for medico-biological preparations].

A variant of Vero cell line has been obtained, adapted to the Russian Eagle's medium with 8% fetal calf serum. The variant is characterized by intensive cell proliferation, possesses a different content of chromosomes, contains no oncogens and contaminants, specifically, Mycoplasma. The strain was characterized and certified in accordance with the WHO requirements.

[Constructing the reference panel of sera with standard level of IgG-antibodies].

Fundamentals of designing reference panels of sera for effective control of commercial test systems and immunoblotting, intended for detecting antiviral antibodies, have been developed. Reference low-titer panels of anti-IgG antibodies to HIV-a and hepatitis C virus have been designed. A reference panel contains diluted reactive sera with a standard level of IgG antibodies and native sera with undetectable level of antibodies to the major viral antigens from risk group subjects.

[Isolation and characteristics of a new strain of diploid cells from human embryonic lung tissue].

A new strain of the embryonic human fibroblasts L-68 was obtained and thoroughly characterized. It completely met all the requirements of the International Committee on the Cells Cultures. This strain can be recommended as a substrate for production of viral vaccines, diagnostic preparations and for research purposes.

[Comparative evaluation of methods for detecting HBsAg in sera].

The results of the analysis of 1209 serum samples, made with a view to detecting those containing HBsAg, are presented. This analysis was made by the radioimmunoassay (RIA) on a polyethylene film, by the standard RIA technique with the use of a diagnostic kit obtained from Abbott Laboratories (USA) and by the passive hemagglutination (PHA) test. The RIA film technique was found to have the sensitivity of about 2 ng/ml HBsAg, which is similar to the sensitivity of the kit from Abbott Laboratories and exceeds the sensitivity of the PHA test approximately 50-fold.

[Use of a radioimmune method for determining HBsAg in preparations of human gamma-globulin].

The work presents the results of studies made with a view to improve the method of testing gamma-globulin preparations for the presence of hepatitis B virus surface antigen (HBsAg) by means of radioimmunoassay (RIA). The work shows that this method requires the use of specially selected negative control samples made up of pooled gamma-globulin samples. Standard RIA techniques intended for detecting the presence of HBsAg in human plasma and blood serum is not suitable for the analysis of the preparations of human gamma-globulin.

[Use of a cocultivation method for detecting cytomegalovirus contamination of cell cultures of simian origin].

At present, nonanthropoid primates are widely used as sources of cell cultures for manufacture of live viral vaccines. Simian cell cultures, particularly kidney cell cultures are also known to be frequently contaminated with cytomegaloviruses. The isolation of the latter is rather difficult due to the late appearance of the cytopathic effect in cell cultures of natural hosts.

[Helper viruses of adeno-associated virus type 4 replication].

In replication of adeno-associated virus type 4 (AAV-4) the helper function may be performed by a non-defective virus from the same group of parvoviruses (Kilham virus). The synthesis of AAV-4 antigen was observed in a pig embryo kidney cell line, SPEV, chronically infected with Kilham virus, strain RV-13, 45--52 passages. A one-day-old SPEV-Kilham culture was infected with AAV-4.

[Modification of chromosome aberrations caused by kilham virus in rat embryo cells].

Mutagenic effect of Kilham virus on the frequency of chromosome aberrations in the cells of primary and continous rat embryo cultures and the modification effect of cadmium salt on the mutagenic potential of this virus was studied. The frequency of chromosome aberrations increased in the primary rat embryo culture after Kilham virus enfection. Rat embryo culture chronically infected with Kilham virus did not differ from control continuous cells in the frequency level of chromosome aberrations.