[Efficacy of combined administration of ridostin and oseltamivir (tamiflu) for therapy and prophylaxis of experimental infection induced by influenza virus A (H5N1) in mice].

AIM: Study of possibility of treatment-prophylaxis effect increase during combined administration of ridostin and tamiflu in experiments in mice infected with highly pathogenic influenza virus strain A/chicken/Kurgan/05/2005 (H5N1). MATERIALS AND METHODS: Balb/c line mice infected intranasally with influenza virus at 100 and 10 LD50 doses received ridostin and tamiflu as monopreparation or the combined variant before or after the infection. The mice were observed for 16 days, lethality rate, protection coefficient and average life span were evaluated. Virus concentration in lungs was determined by using titration in MDCK cell line. RESULTS: Combined administration ofridostin and tamiflu after the infection increased survivability of the animals when compared with the control group, and reduced influenza virus concentration in lungs. CONCLUSION: Treatment effect during combined administration of ridostin and tamiflu after influenza virus infection increased.

[The application of xMAP technology in genetic typing of measles virus].

The genetic typing of measles virus in clinical samples using xMAP technology was applied. The study provided the calculation and application of specific oligonucleotide probes of genotypes D4, D6 and D7 of measles virus. The strain HobO96 genotype A of measles virus as a check sample was used. The technical approaches to the optimization of preparatory work organization and to the process of identification of measles virus genotypes are described. The presence of genotypes D4, D6 and D7 in clinical samples is proved by the sequence analysis. The genetic typing effectiveness of technique of DNA hybridization using xMAP technology on the instrumental base BioPlex (BioRad, USA) is demonstrated.

[Evaluation of immunogenicity and safety of 2 immunizations with allantoic intranasal live influenza vaccine Ultragrivac].

AIM: Evaluate reactogenicity, safety and immunogenicity in phase 2 clinical trials of 2 immunization schedules with Ultragrivac--an allantoic intranasal life influenza vaccine based on A/17/ duck/Potsdam/86/92 [17/H5] reassortant strain. MATERIALS AND METHODS: 4 groups of volunteers participated in the study: group 1--40 individuals were vaccinated twice with a 10 day interval; group 2--40 individuals were vaccinated twice with a 21 day interval; group 3 (control)--10 individuals received placebo twice with a 10 day interval; group 4 (control)--10 individuals received placebo twice with a 21 day interval. Local (secretory IgA), cellular and humoral immune response were evaluated. Humoral immunity was evaluated by the intensity of increase of geometric mean antibody titers against 2 influenza virus strains A/17/duck/Potsdam/86/92 [17/H5] and A/chicken/Suzdalka/Nov-1 1/2005 (H5N1), and by the level of significant (4 times or more) antibody seroconversions after the vaccination. RESULTS: After the use of Ultragrivac the level of secretory IgA in the nasal cavity of vaccinated volunteers in the groups with revaccination intervals of 10 and 21 days increased significantly. The second immunization with 10 or 21 day intervals significantly increased postvaccinal humoral immune response. Humoral immune response induction after 2 vaccinations with 10 day interval was no less effective than with 21 day interval. CONCLUSION: Ultragrivac allantoic intranasal live influenza vaccine is areactogenic, harmless for vaccinated individuals, safe for those around, and has immunogenic properties against not only homologous virus A(H5N2), but also against influenza strain A(H5N1).

[Studies of properties of pandemic influenza virus A/H1N1 circulated in Russian Federation in 2009 - 2010].

AIM: Studies of cultural, virologic, antigenic properties of 89 samples of pandemic influenza A(H1N1) 2009 virus isolated in Russian Federation from May 2009 to March 2010. MATERIALS AND METHODS: Properties of isolated samples were compared with those of the reference strain A/ California/04/2009 (H1N1). RESULTS: Studies of biological properties and analysis of genome nucleotide sequences of the isolated samples showed that those strains are closely related to the reference strain. CONCLUSION: Monitoring of genetic, virologic and antigenic properties of pandemic influenza A(H1N1) 2009 virus isolates carried out from May 2009 to March 2010 did not reveal significant changes in the abovementioned properties of the virus or emergence of mutations that can lead to such changes.

[In vitro and in vivo efficacy of Ingavirin against strains of pandemic influenza virus A(H1N1/09)v].

AIM: To study efficacy of Ingavirin in vitro and in vivo against strains of pandemic influenza virus A(H1N1/09)v and influenza virus A(H5N1) and A(H3N2). MATERIALS AND METHODS: Changes in hemagglutinating and cytopathic activity of influenza virus strains A(H1N1/09)v, A(H5N1) and A(H3N2) during their incubation in the presence of Ingavirin or Remantadin on MDCK cell culture were studied. In mice infected by influenza strains A(H1N1/09)v and A(H3N2) and orally treated with Ingavirin, Tamiflu or Remantadin virus titers in lungs were measured. RESULTS: There was decrease in hemagglutinating and cytopathic activity of influenza virus strains after incubation with Ingavirin in vitro. Ingavirin effectively inhibited reproduction of influenza virus strains A(H1N1/09)v and A(H3N2) in lungs of infected mice. Titers of these strains in lung homogenates decreased when Ingavirin was orally administered to infected mice. CONCLUSION: Strains of influenza virus A(H1N1/09)v were susceptible to Ingavirin and Tamiflu but resistant to Remantadin. Reference strains of A(H5N1) and A(H3N2) were susceptible to Ingavirin, Tamiflu and Remantadin.

[Study of efficacy of anaferon pediatric in mice infected by pandemic influenza virus A(H1N1/09)v].

AIM: To study efficacy of anaferon pediatric in mice infected by pandemic influenza virus A(H1N1/09)v. MATERIALS AND METHODS: Influenza virus strain A/California/07/2009 (H1N1)v was used. Three groups of BALB/c mice intranasally inoculated with influenza virus were studied. First group received solution of Anaferon pediatric during 5 days before and 8 days after inoculation, 2nd group received Tamiflu during 5 days after inoculation. Distilled water was administered orally to mice from control group. RESULTS: It was shown that Anaferon pediatric used as preventive and treatment agent in mice intranasally inoculated with 100% infectious dose of influenza virus strain A/ California/07/2009 (H1N1)v had antiviral effect, which expressed in 10-fold decreased reproduction of influenza virus in lungs of infected mice compared to control group measured 4, 6, and 8 days after inoculation. CONCLUSION: Use of anaferon pediatric before and after inoculation with influenza virus A(H1N1/09)v was not less effective than use of Tamiflu after inoculation.

[Pandemic influenza virus A (H1N1) in Amur region in autumn 2009].

AIM: Isolation and study of molecular genetic characteristics of pandemic influenza virus A (H1N1) circulated in Amur region in autumn 2009 as well as testing of serum samples taken from citizens of this region during November- December 2009 in order to measure levels of antibodies to socially significant serotypes of influenza A virus. MATERIALS AND METHODS: Strain of pandemic influenza virus A/Blagoveschensk/01/2009 (H1N1) was isolated on MDCK cell culture and nucleotide sequences of all eight segments of viral genome were determined. Five hundred seventy-six serum samples taken in Amur region in autumn 2009 were tested by hemagglutination inhibition assay. RESULTS: Nucleotide sequence of A/Blagovechensk/01/2009 (H1N1) strain was 99.7% identical to reference influenza virus strain A/California/04/2009. Diagnostically significant titers of antibodies to pandemic influenza virus were observed in 46.3% of persons younger 30 years old and in 20.1% older persons. Antibodies to seasonal influenza virus H1N1 and H3N2 were detected in 39.5 and 29.8% of persons respectively. CONCLUSION: Final seroepidemiological picture of distribution of pandemic virus in Amur region matches with the one for seasonal influenza virus A (H1N1): > 60% of seropositive persons were registered in age group < 18 years old, and this proportion increases with increasing age.

[Study of antiviral activity of extracts obtained from basidial fungi against influenza viruses of different subtypes in experiments in vitro and in vivo].

AIM: To study antiviral activity of extracts obtained from basidial fungi against influenza viruses of different subtypes. MATERIALS AND METHODS: Antiviral activity of extracts obtained from basidial fungi against influenza virus A/chicken/Kurgan/05/2005 (H5N1) was determined in in vitro experiments. Changes in infectiousness of pandemic influenza virus A/Moscow/226/2009 (HIN1)v caused by extracts of basidial fungi was studied in experiments in vitro and in vivo. RESULTS: Seventy water extracts of basidial fungi were studied, of which 10 were able to inhibit infectiousness of influenza virus strain A/ chicken/Kurgan/05/2005 (H5N1) in MDCK cell culture. Also, several studied extracts decreased infectiousness of pandemic influenza virus strain A/ Moscow/226/2009 (H1N1)v in MDCK cells and inhibit its reproduction in lungs of infected mice. CONCLUSION: High antiviral activity of extracts obtained from basidial fungi against influenza viruses opens perspectives for development of drugs with preventive and treatment effects.

[Development of new nutrient medium for MDCK and Vero cells based on soy hydrolysate obtained using bromeline and assessment of growth characteristics of influenza virus vaccine strains cultivated on them].

AIM: To develop nutrient medium for MDCK and Vero cells based on soy hydrolysate obtained using bromeline and to assess of growth characteristics of influenza virus vaccine strains cultivated on them. MATERIALS AND METHODS: Physico-chemical characteristics of hydrolysate were assessed according to FS 42-3874-99. Growth characteristics of nutrient medium based on soy hydrolysate and vaccine strains of influenza virus A/Solomon Islands/03/06 (H1N1), A/Wisconsin/67/2005 (H3N2) and B/Malaysia/2506/2004 were studied on MDCK and Vero cells. RESULTS: MDCK and Vero cells grew well on medium based on soy hydrolysate obtained using bromeline with decreased (to 2% and 3% respectively) content of fetal calf serum and allowed effective production of vaccine strains of influenza virus. CONCLUSION: Technology for producing of nutrient medium based on hydrolysate of soy flour obtained using bromeline was developed. This medium could successively used for cultivation of continued cell cultures MDCK and Vero used as substrate for tissue culture-based vaccines against influenza.

[Genetic variability of isolates of pandemic influenza A virus H1N1 isolated in Russia in 2009].

Complete nucleotide sequence of the genome segments encoding the surface glycoproteins, hemagglutinin, and neuraminidase of influenza A virus H1N1 derived from the patients with influenza in the context of pandemic (H1N1) 2009 was determined out of 14 isolates of pandemic influenza. The philogenetic analysis of these sequences demonstrated their genetic similarity to the corresponding genes of the pandemic influenza virus A (H1N1) 2009 isolates obtained in other countries; each gene homology was greater than 99%. Neuraminidase mutations causing virus resistance to oseltamivir and other neuraminidase inhibitors, known from the literature, were not detected. The hemagglutinin gene mutation D222G was found in 4 isolates from autopsy material. In the hemagglutinin of pandemic A/Salekhard/01/2009(H1N1) isolate a mutation G155E leading to the increase in viral replication in developing chick embryos was detected. The nature and frequency of nucleotides substitutions within HA and NA genes were determined in the current research.

Antiviral activity of Anaferon (pediatric formulation) in mice infected with pandemic influenza virus A(H1N1/09).

Anaferon (pediatric formulation) administered in the therapeutic-and-prophylactic regimen to mice receiving intranasally 100% infecting dose of A/California/07/2009(H1N1)v influenza virus exhibited an antiviral effect and 10-fold reduced the production of influenza virus in the lungs of infected mice on days 4, 6, and 8 after infection compared to the control (distilled water). The efficiency of Anaferon (pediatric formulation) administered before and after infection with A/California/07/2009(H1N1)v influenza virus was not inferior to the use of Tamiflu after infection.

[In vivo efficacy of Ingavirin against pandemic A (H1N1/09)v influenza virus].

Ingavirin was shown to be efficient in inhibition of the pandemic influenza virus strains A/California/04/2009 (H1N1)v, A/California/07/2009 (H1N1)v, A/Moscow/225/2009 (H1N1)v and A/Moscow/226/2009 (H1N1)v. as well as the influenza virus strain A/Aichi/2/68 (H3N2) in the lungs of the infected mice. After oral administration of Ingavirin the titers of the influenza virus strains in the lung homogenates lowered.

Surveillance and identification of influenza A viruses in wild aquatic birds in the Crimea, Ukraine (2006-2008).

The ecology of avian influenza (AI) viruses in wild aquatic birds of Asia is poorly understood, especially for the H5N1 high pathogenicity AI (HPAI) viruses. From March 2006 through November 2008, 20 AI viruses were isolated in the Crimea region of Ukraine with an overall frequency of virus recovery of 3.3%. All the viruses were isolated from three species of dabbling ducks: mallard (Anas platyrhynchos), wigeon (Anas penelope), and garganey (Anas querquedula), making the frequency of virus recovery for dabbling ducks 6.3%. The viruses were predominantly isolated during the fall sampling period. All viruses were genetically and antigenically characterized. No H5N1 HPAI viruses were isolated, but other HA and NA subtypes were identified including H3N1 (2), H3N6 (3), H3N8 (4), H4N6 (6), H5N2 (3), H7N8 (1), and H10N6 (1) subtypes. All isolates were of low pathogenicity, as determined by the intravenous pathogenicity index of 0.00. For H5N2 and H7N8 isolates, the HA gene was sequenced and the phylogenetic analysis revealed possible ecologic connections of the Crimea region with AI viruses from Siberia and Europe. No influenza A isolates were recovered from other Anseriformes (diving ducks [two species of pochards] and graylag geese), Columbiformes (collared doves), Gruiformes (coot), and Galliformes (gray partridges).

[In vitro efficacy of Ingavirin against the pandemic influenza virus A(H1N1/09)v].

Ingavirin was shown to be efficient in inhibition of the influenza virus strains A/California/04/2009 (H1N1)v, A/California/07/2009 (H1N1)v, A/Moscow/225/2009 (H1N1)v and A/Moscow/226/2009 (H1N1)v, as well as the strains A/Chicken/Kurgan/05/2005 (H5N1) and A/Aichi/2/68 (H3N2) in the MDCK cell culture. The hemagglutinin and cytopathic activity of the influenza virus strains decreased at entering Ingavirin in vitro.

[Detection of antibodies to A/H5N1 influenza virus in citizens of Russian Federation].

AIM: To determine levels of antibodies to influenza virus A/H5N1 in serum samples of people living in different regions of Russia in order to assess the risk of infection with avian influenza H5N1. MATERIALS AND METHODS: Two thousand one hundred sixty-eight serum samples were tested by hemagglutination inhibition assay for the presence of antibodies to influenza virus A/H5N1. RESULTS: Twenty-six serum samples obtained from residents of Khanty-Mansiysk Autonomous Area and 2 samples from residents of Novosibirsk region were positive for antibodies to serotype A/H5. There were no clinical cases of avain influenza A/H5N1 infection in medical history of studied persons. CONCLUSION: Since cases of asymptomatic carriage of A/H5N1 influenza virus in water birds are described and ability of the virus to survive in water environment for a long time is shown, it seems logical to detect antibodies to influenza virus A/H5 in sera of subjects living in Russian Federation taking into account that influenza virus A/H5N1 is isolated from wild fowl and poultry since 2005.

[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.

[Characteristic of high pathogenic avian influenza virus subtype H5N1 isolated from common gull (Larus canus)].

AIM: To study biological characteristics of H5N1 influenza virus isolated from common gull on south of West Siberia in 2006. MATERIALS AND METHODS: Isolation and characterization of biological characteristics performed according to recommendations of World Health Organization. RESULTS: Influenza virus A (H5N1) was first isolated from common gull (Larus canus) in Russia. Antigen of isolated virus had significant affinity to polyclonal sera obtained against high pathogenic avian influenza viruses H5N1 circulating in South-East Asia. Phylogenetic analysis of isolated strain revealed its belonging to group of Qinghai-related variants of H5N1 influenza virus. Aminoacid structure of hemagglutinin proteolytic cleavage site is characteristic for type A high pathogenicity avian influenza viruses. Experimental infection of chickens demonstrated high pathogenicity of the isolated virus. CONCLUSION: Involvement of common gulls in circulation of subtype H5N1 influenza virus is demonstrated for the first time. Important role of species from Laridae family in unprecedented spreading of H5N1 influenza virus started in 2005 is discussed.

[Monitoring for influenza in population of Western Siberia in 2007-2009].

AIM: To analyze influenza viruses isolated in the 2008-2009 autumn-winter season, and to test sera collected in the south of Western Siberia during the beginning and the end of the epidemic seasons from 2007 until the A/H1N1 pandemic. MATERIALS AND METHODS: Total 149 clinical samples were analyzed and 2190 blood sera were tested. During the 2008-2009 season 17 influenza viruses were isolated. 9 of these were A/H1N1, 5-were A/H3N2, and 3 were influenza B viruses. The nucleotide sequences and amino acid composition of influenza A virus hemagglutinin (HA) were compared with reference strains. RESULTS: Among A/H1N1 viruses circulating in Novosibirsk region three viruses contained four amino acid replacements in antigen sites Ca, Cb and Sb. In A/ H3N2 viruses from Novosibirsk, 2 amino acid substitutions were detected in antigen sites B and E. CONCLUSION: Based on genotyping influenzae epidemic on February to April of 2009 in the south of western Siberia was associated with influenza viruses A/H1N1, A/H3N2, and B. All A/H3N2 influenza virus isolates were variants of reference A/Brisbane/10/2007(H3N2) and A/ H1N1 influenza viruses isolates were similar to reference A/Brisbane/59/2007(H1N1).

[Isolation of influenza A virus from wild birds in western part of Mongolia].

AIM: To study circulation of influenza A viruses in western part of Mongolia. MATERIALS AND METHODS: Isolation and characterization of influenza viruses was performed according to recommendations of WHO. RESULTS: Circulation of influenza A viruses subtypes H3N6, H4N6, H1N1, H13N8 in different wild bird species in western part of Mongolia was documented. CONCLUSION: Taxonomic and ecologic heterogeneity of bird species involved in continuous circulation of influenza A viruses was revealed. Subtype H13N8 was isolated for a first time from herring gull on territory of western Mongolia.

[Monitoring of antibodies to influenza A virus in populations of different regions of West Siberia].

AIM: To study levels of antibodies to influenza virus in sera of subjects residing in different regions of West Siberia in order to assess the risk of infection with avian influenza virus H5N1. MATERIALS AND METHODS: Two hundred and sixty-five serum samples were tested for the presence of antibodies to influenza virus A/New Caledonia/99 (H1N1), A/New York/55/2005 (H3N2), A/Whooper swan/ Mongolia/244/2005 (H5N1) by hemagglutination inhibition assay (HAI) and reaction of microneutralization. RESULTS: All tested sera were negative for antibodies to H5N1. 14.2% and 44.1% of sera were positive for antibodies to H1N1 in HAI and reaction of microneutralization respectively. In respect of antibodies to H3N2 virus, the proportion of positive sera was higher--40.3% and 76.2%, respectively. CONCLUSION: Results of such studies are very actual, especially during pandemic threat. Furthermore, such information allows to better predict consequences of seasonal influenza epidemics caused by serotypes circulating at the present time.