[Results of clinical trials on reactogenicity, safety, and immunogenicity of influenza allantoic intranasal live vaccine "Ultragrivac" (type A/H5N2)].

Results of phase II of a clinical trial of the influenza allantoic intranasal live vaccine "Ultragrivac" (type A/H5N2) are presented. The vaccine was developed based on strain /17/Duck/Potsdam/86/92 H5N2 [17/H5] - reassortant of two viruses, /Leningrad/134/17/57 (H2N2) and /Duck/Potsdam/1402-86 (H5N2), obtained from the Virology Department, St. Petersburg Institute of Experimental Medicine.Two schemes of immunization (with revaccination on days 10 and 21) were used. Evaluation of vaccine immunogenicity included determination of local, cellular and humoral immunity. A significant rise in the level of secretory IgA in the nasal cavity of vaccinated volunteers (with revaccination on days 10 and 21) was documented after application of the vaccine. The postvaccination humoral immune response was estimated from the level of significant (4-fold and more) antibody seroconversions, geometric mean titers of antibodies to two strains of influenza virus /17/Duck/Potsdam/86/92 H5N2 [17/H5] and /Chicken/Suzdalka/Nov-11/2005 (H5N1), and their incremental rate. Results of measurement of antibody titers in hemagglutination-inhibition assay are presented, with two antigens being used to analyse all serum samples from volunteers twice vaccinated with influenza vaccine "Ultragrivac" at 10 and 21 day intervals. Result of phase II of this clinical study show that influenza allantoic intranasal live vaccine "Ultragrivac" is nonreactogenic and safe for both vaccinated and surrounding individuals. Moreover, it is sufficiently immunogenic with respect not only to homologous virus A(H5N2) but also to the A(H5N1) strain.

[Clinical trial of safety and immunogenicity of new influenza vaccine Grifor in children].

AIM: Assessment of reactogenicity, safety and immunogenicity after single intramuscular immunization of children with Grifor vaccine. MATERIALS AND METHODS: Reactogenicity, safety, and immunogenicity of Grifor vaccine compared with Vaxigrip vaccine was evaluated during phase III clinical trial in the Institute of Influenza. Thirty-six children aged 12 - 17 years, divided on 2 groups, participated in single blind comparative prospective randomized trial. Seroconversion factor, seroconversion and seroprotection levels were evaluated by hemagglutination inhibition assay. RESULTS: Results of study of systemic and local reactogenicity in children during first 7 days after immunization with Grifor and Vaxigrip vaccine showed good tolerability, areactogenicity and safety of both vaccines. Complete blood count, serum biochemistry and urinalysis results as well as serum IgE level did not change after vaccination. After immunization with Grifor vaccine, seroconversion rate to influenza virus subtypes A/H1N1, A/H3N2, and B was 70%, 50%, and 70% respectively, seroprotection rate--90%, 80%, and 85% respectively, and seroconversion factor--6.5, 2.7, and 4.0 respectively. CONCLUSION: This trial, which was performed in tightly controlled conditions, had demonstrated that Grifor vaccine is safe and highly immunogenic against influenza viruses A and B and satisfies criteria of both Federal Service for Surveillance for Protection of Consumers Rights and Human Welfare and CHMP of EMA. Obtained results allow to recommend the Grifor vaccine for use in pediatric practice according to national immunization schedule.

[Development and preclinical study of new generation virosomal split influenza vaccine "Grifor"].

New Russian virosomal split vaccine against influenza "Grifor" was developed. The vaccine is represented by mix of highly purified protective external and internal antigens of influenza A (H1N1 and H3N2) and B viruses. Developed technology of manufacture allowed to provide presentation of external antigens of influenza virus in the form of virosomes, and presentation of internal antigens in the form of micelles with maximal preservation of their antigenic activity. Using electron microscopy, electrophoresis in 10% polyacrilamide gel with sodium dodecyl sulfate, and polymerase chain reaction, morphologic and biochemical properties of the vaccine were studied. Preclinical study, including assessment of antigenic characteristics of "Grifor" vaccine compared to vaccine "Vaxigrip" (France), was performed. It was established that administration of the vaccine did not result in death of experimental animals, decrease of body mass, development of pathologic (including inflammatory, dystrophic and necrobiotic) changes in viscera or render adverse effects on blood hematologic and biochemical parameters and on the immune system. The vaccine was not pyrogenic and allergenic, did not have local irritating effects. Obtained results supported the appropriateness of conducting the clinical trials of "Grifor" vaccine on limited number of volunteers.

[Study of reactogenicity, safety and immunogenicity of inactivated virosomal split influenza vaccine "Grifor" during phase I clinical trial].

Phase I clinical trial of inactivated virosomal split influenza vaccine "Grifor" was conducted in the Mechnikov Research Institute of Vaccines and Sera as accredited base for such trials. Forty healthy volunteers (males and females) aged 18 - 50 years consented to participate in the trial. Reactogenicity, safety, and immunogenicity of new Russian influenza vaccine were assessed. Analysis of obtained results showed that there was evidence of safety and low reactogenicity of the vaccine as well as of its high immunogenic characteristics, which satisfied both the EMEA's Committee for Proprietal Medicinal Products criteria and requirements of Federal Service for Surveillance for Protection of Consumers Rights and Human Welfare (MU 3.3.2.1758-03) for inactivated influenza vaccines.

[Clinical trial of new inactivated influenza vaccine "Grifor"].

AIM: To confirm and prove on the extended contingent of volunteers the non-reactogenicity, safety and immunogenicity of "Grifor" vaccine in comparative trial with registered in Russia commercial vaccine "Vaxigrip". MATERIALS AND METHODS: Phase II clinical trial was performed on the research bases of Mechnikov Institute of Vaccines and Sera and Institute of Influenza. In single-blind comparative prospective randomized trial 300 adult volunteers (150 volunteers on each base) aged 18 - 60 y.o. were divided on 3 equivalent groups. Assessment of antigenic characteristics of "Grifor" vaccine was performed using hemagglutination inhibition assay (HAI) with chicken erythrocytes measuring geometric mean titer (GMT), seroconversion factor as well as level of seroconversion and seroprotection. RESULTS: Previously performed studies proved non-reactogenicity, safety and high immunogenicity of "Grifor", whereas this comparative trial performed with commercial vaccine "Vaxigrip" did not reveal significant advantage in any of studied vaccine. CONCLUSION: "Grifor" vaccine meet the requirements of both EMEA CPMP and methodic guidelines MY 3.3.2. 1758-03 for inactivated influenza vaccines, which allows to register vaccine "Grifor" in Russian Federation.

[Tetravaccine--new fundamental approach to prevention of influenza pandemic].

According to opinion of WHO's experts, development and use of tetravaccine, which contains both interdemic and pandemic (H5N1) serotypes of influenza viruses, is one of the most promising approaches to control possible influenza pandemic. Results of recently obtained data from clinical trials allowed experts from WHO to make a conclusion that protective immunity against avian influenza virus can be achieved after 2-doses immunization, when the immune system will be primed to hemagglutinin after the 1st dose and sufficient protective immunity level will be formed after the 2nd dose. However, in case of real threat of pandemic, the time for immunization with 2 doses of the vaccine will be absent. In order to provide protection for population of Russia in a limited time frame it is reasonable to vaccinate them with H5 hemagglutinin beforehand. In that case, when real threat of pandemic will arise, not two but one injection with monovalent vaccine against avian influenza will be sufficient. This idea formed the basis for concept of development of tetravaccine. The essence of the concept is vaccination of population with tetravaccine, consisting of antigens of influenza virus serotypes H3N2, H1N1, B, and H5, before the influenza pandemic caused by H5N1 virus will begin. Such vaccination will induce immunologic memory to hemagglutinin of avian influenza virus serotype H5 and, when the real threat of the pandemic will occur, only single immunization with monovaccine against avian influenza instead of 2 doses will be required. In 2006 Scientific-Production Association "Microgen" conducted extended preclinical study of immunogenic and protective characteristics of candidate vaccines against avian influenza prepared from vaccine strains of H5N1 and H5N2 serotypes. It has been shown that candidate vaccines prepared from both strains have high protective ability against Russian epidemic isolate A/chicken/Kurgan/Russia/2/2005(H5N1). To this time Scientific-Production Association "Microgen" has produced monovalent bulk of H3N2, H1N1, and B serotypes, which are included in interdemic influenza vaccines, as well as monovalent bulk of H5N1 and H5N2 serotypes. This intermediate products are ready to be produced into tetravaccine for conducting extended preclinical studies of its safety, reactogenicity, immunogenicity, and protective properties. If results of such studies will be positive then it is possible to begin clinical trials of the tetravaccine in 2007 and to discuss the questions about its dosage, methods of challenge and schedule.

[Comparative clinical trial of vaccines against avian influenza].

Scientic-production association "Microgen" has finished 1st phase of clinical trials of candidate vaccines against avian influenza in order to assess their reactogenicity, safety, and immunogenicity. Two vaccines constructed from NIBRG-14 vaccine strain [A/Vietnam/1 194/2004 (H5N1)], obtained from World Health Organization, were studied: "OrniFlu" (inactivated subunit influenza vaccine adsorbed on aluminium hydroxide) and inactivated polymer-subunit influenza vaccine with polyoxydonium (IPSIV). Clinical trial of the vaccines with different quantity of antigen (15, 30, and 45 mcg of H5N1 virus hemagglutinin) was carried out in Influenza Research Institute (St. Petersburg) and in Mechnikov Research Institute of Vaccines and Sera (Moscow). Analysis of results allowed to conclude that both vaccines were safe, well tolerated and characterized by low reactogenicity. Two-doses vaccination schedule was needed to meet required seroconversion and seroprotection rates (> or =1:40 in > or =70% of vaccinated volunteers). "Orni-Flu" vaccine containing 15 mcg of hemagglutinin and optimal quantity of aluminium hydroxide (0.5 mg) in one dose as well as IPSIV containing 45 mcg of hemagglutinin and 0.75 mg of polyoxydonium in one dose were most immunogenic after 2 doses - seroprotection rates in microneutralization assay were 72.2% and 77.0% respectively. Marked influence of aluminium hydroxide content on immunogenicity of the "OrniFlu" vaccine was confirmed in the study. Optimal quantity of adjuvant was 0.5 mg per dose. According to basic concept of vaccine development, preference is given to vaccine that under minimal quantity of antigen induces sufficient specific immune response and is safe in volunteers. "OrniFlu" vaccine containing 15 mcg of H5N1 virus hemagglutinin and optimal quantity of aluminium hydroxide (0.5 mg) corresponded to these requirements that allowed researchers to recommend it for clinical trials of 2nd phase.

[Interaction of the M protein of the wild-type fowl pest virus and its ts-mutant with the ribonucleoprotein of the fowl pest virus in vitro]. / Vzaimodeistvie belka M virusa chumy ptits dikogo tipa i ts-mutanta s ribonukleoproteidom virusa chumy ptits in vitro.

The extent of inhibition of transcription realized in vitro by fowl plague virus (FPV) ribonucleoprotein (RNP) upon the addition of M protein isolated from FPV virions does not depend on nonionic detergent concentration in the reaction medium but does depend greatly on NaCl concentration. The highest inhibition of transcription is observed at a low ionic strength (0.02 M NaCl); inhibition is completely eliminated by increasing NaCl concentration to 0.3 M. When M protein isolated from FPV virions with ts mutation of M protein is added to RNP, addition to the system of 0.3 M NaCl decreases transcription inhibition but does not eliminate it completely.

[Some properties of the alpha-hemolysin produced by a hemolytic strain of E. coli]. / Nekotorye svoistva al'fa-gemolizina, produtsiruemogo gemoliticheskim shtammom E. coli

It was found that alpha-hemolysin of E. coli P 678 HIy+ was maximally active against human erythrocytes at pH 6.5. The hemolytic activity is characterized in time by a distinct lag-phase and a phase of the greatest velocity of the reaction immediately following it. The duration of the lag-phase and also the rate of hemolysis depends on alpha-hemolysin concentration, whose increase is accompanied by a decrease of the lag-phase and acceleration of hemolysis. There is a definite limit below which the duration of the lag-phase remains unchanged with further increase of hemolysin concentration. There was noted a linear relationship between the amount of erythrocytes taken for the test and the rate of hemoglobin release and also a temperature activation of the hemolytic reaction.