[The peculiarities of the influenza epidemics in some areas of Russia during 2012-2013 season. The influenza A (H1N1) pdm09 virus domination in European countries].

The peculiarities of the influenza viruses circulation in 2012-2013 are discussed. The results were obtained in 10 cities of Russia, where basic laboratories of the Influenza Ecology and Epidemics Center of on the basis of Ivanovsky Institute of Virology, Ministry of Health of the Russian Federation, are situated. The increasing rate of the ARD morbidity caused by influenza viruses was observed in January-March 2013. The highest indices of the morbidity were detected during 6-7 weeks with the following decreasing rate till threshold levels to week 14. The influenza A (H1N1) pdm09, A (H3N2), and B viruses were the cause of the epidemic, but their activity differed over areas of Russia. The results of study of the antigenic and genetic properties of the influenza strains demonstrated closed relatives with respect to vaccine strains. In addition, some heterogeneity of the circulating strains and their drift variants were found as well. All tested strains were sensitive to oseltamivir (excluding one A (H1N1) pdm09 strain), zanamivir, arbidol, and remained resistant to rimantadine. The ratio of the ARD viruses was comparable with the last epidemic seasons.

[Development of the influenza epidemic in season 2011-2012 in some areas of Russia: results of activity of the Influenza Etiology and Epidemiology Center of the Ivanovsky Institute of Virology].

The results of analysis of the peculiarities of the epidemic 2011-2012 development in the areas of 10 cities of Russia obtained by basic laboratories of IEES on the base of D.I. Ivanovsky Research Institute of Virology, Ministry of Public Health and Social Development of Russia, are presented. The increasing ARD morbidity caused by the influenza viruses was detected rather late--in February-March 2012. The highest indices of the morbidity were detected during weeks 10-13 followed by decreasing to threshold levels by week 27. Children 0-2 and 3-6 years old were involved the most, meantime the high rate of hospitalization was found for 15-64 years old aged group (25%). Influenza A(H3N2) and B viruses were the cause of the epidemic. The results of studies of the antigenic and genetic properties of the influenza strains showed most of them to be close relatives to the vaccine strains. Some heterogeneity of circulating strains and their drift variants were found as well. All tested strains were sensitive to arbidol, oseltamivir and zanamivir, and saved resistance to rimantadine. The ratio of ARD viruses was comparable with the last epidemic seasons.

[The specific features of the cocirculation of influenza viruses in the 2010-2011 postpandemic period according to the results of activities of the D. I. Ivanovsky Research Institute of Virology, Ministry of Health and Social Development of Russia].

The paper gives the results of monitoring the circulation of influenza viruses in the 2010-2011 season, that covers the second year of circulation of pandemic A(H1N1)v virus strains, and their interaction with seasonal A (H3N2) and B strains. Unlike the previous season, the beginning of an increase in morbidity was recorded in January 2011; its peak in the most of contiguous areas was noted at 5-7 weeks of 2011, with its further decline to threshold levels at week 11 of 2011. Preschool and school children were most involved in the epidemic process. Three influenza virus strains (A(H1N1)v, A(H3N2), and B) were found to circulate. Differences were found in the level of participation of the isolated strains in individual areas of the Russian Federation. Detailed typing of the isolated strains determined the compliance of the vast majority of them with vaccine viruses. The pandemic influenza A(H1N1)v virus strains retained their susceptibility to oseltamivir and were resistant to rimantadine. The participation of non-influenza acute respiratory viral infection pathogens was estimated as follows: 11.9% for parainfluenza viruses, 5.9% for adenoviruses, and 3.5% for PC viruses, and 0.7% for pneumonia Mycoplasma, which was comparable with the previous epidemic seasons.

[Contribution of D I Ivanovsky Research Institute of Virology to monitoring influenza viruses during epidemics and 2009 pandemic in Russia].

The data on monitoring influenza viruses in Russia are presented based on the research underway at Ivanovsky Research Institute of Virology since 1959. The Institute's priority in isolation and identification of influenza viruses during epidemics and 2009 pandemic is confirmed. Results of assessment of influenza vaccines and etiotropic preparations, development and introduction of new methods for diagnostics of influenza are discussed.

[Spread of new pandemic influenza A(H1N1)v virus in Russia].

The paper presents the results of the investigations of the development of a influenza A(H1N1)v pandemic, conducted by the D. I. Ivanovsky Research Institute of Virology, Russian Academy of Medical Sciences, and collaborating laboratories in the European part of Russia, in the Urals, Siberia, and in the Far East. In the prepandemic period (April 27 - June 11, 2009) its first diagnosis was established on May 21, 2009; the first strain was isolated on May 24, 2009; the data on complete genome sequencing were sent to the GenBank; the sensitivity of the strain to commercial antiviral commercial agents was studied. In the early pandemic period (June 11 - August 15), 73 patients who had come from 14 countries of Europe, America, and Asia were identified; 19 virus strains (partially or completely sequenced) were isolated. The pandemic period (August 15 - December 1) was marked by absolute dominance of pandemic influenza virus virtually in the absence of seasonal influenza; the first death caused by pandemic influenza was detected in late August; 3053 subjects were infected with the pandemic strain, as shown by polymerase chain reaction diagnosis; 202 strains were identified.

[Antineuraminidase activity of inactivated influenza vaccines in elderly people]. / Antineiraminidaznaia aktivnost' inaktivirovannykh grippoznykh vaktsin u lits pozhilogo vozrasta.

The antineuraminidase activity of 5 inactivated split and subunit influenza vaccines (IIV) was studied in individuals aged above 65 years. Postvaccinal antibody titers were determined in the lectin test. All the vaccines were shown to have a high antigenicity, by providing high titers of neuraminidase antibodies in most vaccinated persons: The mean geometric titers (MGT) to influenza viruses A(H1N1) and A(H3N2), and B were 7.4-8.0, 8.5-9.2, and 6.8-8.5 log2, respectively. Neuraminidases showed a higher activity in Vaxigrip-vaccinated persons in terms of both the rate of MGT increases and seroconversion that was 78-84%. The parameters of the anti-neuraminidase (anti-NA) and anti-hemagglutinating (anti-HA) activities of IIV are summarized in the paper. There was a high coincidence of the results of both tests. At the same time it was shown that the postvaccinal humoral immune response might be directed only to one of the surface influenza virus proteins. The highest rate of seroconversions as to the surface antigens of all three influenza viruses was observed in Vaxigrip-vaccinated persons. The paper presents the results of comparison of the levels of MGT of antibodies to both viral surface proteins for all vaccinated with IIV, for those vaccinated who were infected during an epidemic season and a place group. The findings confirmed the value of higher titers of postvaccinal antibodies against influenza infection and illness.

[Immune response following administration of multicomponent vaccine VP-4 in elderly patients]. / Immunologicheskie pokazateli pri vvedenii polikomponentnoi vaktsiny VP-4 litsam pozhilogo vozrasta.

The dynamics of immunological characteristics after the administration of polycomponent vaccine B[symbol: see text]-4 to elderly persons, constituting a risk group with respect to acute respiratory diseases and exacerbations of chronic inflammatory diseases of respiratory organs, was studied. The nasal-oral administration of the vaccine induced immunological shifts in the systems of local and systemic immunity. The content of the populations of lymphocytes with markers CD3, CD4, CD16, CD20 was found to have positive dynamics. Considerable shifts in the system of local immunity were registered: the content of sIgA and IgA in the saliva greatly increased; in addition, an increase in the titers of antibodies to Staphylococcus aureus, Klebsiella pneumoniae and Escherichia coli was observed in persons with initially low titers.

[The choice of the optimal schedules in the vaccination procedure against influenza in elderly subjects]. / Vybor optimal'nykh skhem v taktike vaktsinatsii protiv grippa pozhilykh liudei.

To improve the vaccinal prophylaxis of influenza, the comparative study of live trivalent influenza allantoic vaccine, dried, for adults, produced by the Irkutsk Enterprise for Immunological Preparations (Russia), and inactivated trivalent influenza split vaccine, obtained from Wyeth-Ayerst Company (USA), as well as schedules of their combined use for the vaccination of elderly persons, was carried out. The examination of 600 subjects revealed that the vaccines were well tolerated; the combined use of these two vaccines, as well as the use of the inactivated influenza vaccine (IIV) alone, ensured high immunogenic activity (60.0-80.0% of seroconversions). The live influenza vaccine (LIV) stimulated the production of specific antibodies only in 19.0-35.0% of the vaccinees; most of these vaccinees exhibited positive reaction only to one of the vaccine strains. Following the injection of LIV, the level of postvaccinal immunity was retained for at least 6 months. In the vaccinees receiving both vaccines the tendency towards a decrease in mean geometric titer values was less pronounced (0.2-0.4 log2) than in those receiving only IIV (0.5-0.7 log2). At the period of the rise of influenza morbidity, the contamination rate in the vaccinees with the positive postvaccinal dynamics of antibodies was low (26.0%). The indices of effectiveness were 3.8 for combined vaccination, 3.5 for IIV and 2.6 for LIV. The schedule of vaccination with IIV with the possible revaccination LIV 3-4 weeks later was recommended.

[Current strategies for vaccine prevention of influenza]. / Taktika vaktsionoprofilaktiki grippa na sovremennom étape.

Six-year immunologic surveillance of schoolchildren vaccinated according to different schedules in the town of Novgorod demonstrated the efficacy of overall vaccinations of children and young people with live anti-influenza vaccines in autumn and winter for 2 years. Then an interval of 3 years is to be made, followed by another 2-year revaccination cycle, provided the same serologic subtypes of influenza A and B are still circulating.

[Prophylactic effectiveness of a live recombinant influenza type A vaccine in immunizing children aged 3-14 years]. / Profilakticheskaia éffektivnost' zhivoi grippoznoi rekombinantnoi vaktsiny tipa A pri immunizatsii detei 3-14 let.

Children aged 3 to 14 were immunized with live recombinant influenza A vaccine; about 120,000 children were followed up for 6 months. Analysis of the morbidity (excepting ARVI and influenza) of the immunized and control groups permitted a conclusion about the safety of the preparation. The protective index of vaccine efficacy during influenza epidemic caused by A/Taiwan/1/86(H1N1) virus was 1.3 to 1.42. Live recombinant influenza vaccine is recommended for public health to be used for protection of children aged 3 to 14 from influenza.

[Arbidole--a new drug for prevention of influenza and acute viral respiratory infections in children]. / Arbidol--novoe sredstvo dlia profilaktiki grippa i ostrykh respiratornykh virusnykh infektsii u detei.

The antiviral drug arbidole reduces influenza and acute respiratory diseases (ARD) in children by 1.5-2 times when given in a dose of 0.1-0.2 g 2-3 or 5 times a week, by making influenza and ARD milder and decreasing their duration by 1.4-2.8 days. Unified regimens for prophylactic use of arbidole in influenza and ARD in children and adults are proposed.

[A comparative study of live and inactivated influenza vaccines: the organization of the observation and the results of a study of their reactogenicity and immunogenicity]. / Sravnitel'noe izuchenie zhivoi i inaktivirovannykh grippoznykh vaktsin: organizatsiia nabliudeniia i rezul'taty izucheniia reaktogennosti i immunogennosti.

Schoolchildren of 30 to 34 schools of Novgorod were vaccinated over a three-year period with Russian live cold-adapted attenuated vaccine for children and whole-virus inactivated vaccines and placebo for comparative field study of the vaccines properties and efficacy. In control trials both bi- and trivalent live attenuated vaccines were well tolerated and areactogenic. A whole-virus inactivated trivalent vaccine induced mild and moderate fever and local reactions in 2-4% of the vaccinees. Special observations are necessary to establish the possibility of use and to determine a dose of this inactivated vaccine for immunization of children, especially those of 7-10 years of age. All the vaccines induced HI antibody production in 50-80% and antineuraminidase in 50-70% of seronegative children. The pattern of the results was similar to that in revaccinated children with preexisting antibody at a level of 1:20, but much lower in children with the initial titre above 1:20. After the 3rd year of vaccination the immune response of the vaccinees was similar, most of the results depending on the initial antibody titre and also on the change of vaccine strains. This raises a question of the expediency of annual influenza revaccination of the same person after 2 years of successful immunization and of the necessity of vaccine strains replacement after 2-3 years of use.

[The results of a study of the data obtained from patients vaccinated earlier with different influenza vaccines]. / Rezul'taty issledovaniia materialov, poluchennykh ot bol'nykh, vaktsinirovannykh ranee razlichnymi grippoznymi vaktsinami.

Studies of influenza virus type A and B strains isolated during the epidemics of 1990 and 1991 in Novgorod from sick children previously vaccinated with influenza vaccines demonstrated no influence of postvaccination immunity on the antigenic properties of the isolates from patients with different vaccination history. Under conditions of the concurrent circulation of viruses with previously known and new antigenic structures the difference in the immune response consisted in its greater stimulation of this response to new influenza virus strains.

[A comparative study of the protective properties of live recombinant and inactivated influenza vaccines made from strain A/Philippines/2/82 (H3N2) in 8- to 15-year-old children]. / Sravnitel'noe izuchenie zashchitnykh svoistv zhivoi rekombinantnoi i inaktivirovannoi grippoznykh vaktsin iz shtamma A/Filippiny/2/82 (H3N2) u detei 8--15 let.

A limited controlled comparative study for the evaluation of the epidemiological efficacy of live recombinant and inactivated virion vaccines from A/Philippines/2/82-like strains of influenza A (H3N2) virus was carried out in schoolchildren of 8 to 15 years of age. During the influenza epidemic of 1987-1988 caused by influenza A/Sichuan/2/87 (H3N2)-like strains and by influenza B virus in 8.2-17% of cases, a statistically significant efficacy index for live influenza vaccine was 1.8 for the laboratory confirmed A (H3N2) cases. In the group vaccinated with the inactivated vaccine the number of serologically diagnosed A (H3N2) cases was 1.6 times lower than in the group receiving placebo, this difference being statistically significant. Thus, under the conditions of significant difference in the antigenic structure of the vaccine and epidemic A (H3N2) strains, both vaccines produced some diminished but statistically significant preventive effect in vaccinated children although its level was below the optimal. Revaccination of some children with a live influenza vaccine from a new A/Sichuan/2/87-like variant of A (H3N2) virus in the autumn of 1988 with reisolation of the vaccine strain also revealed the presence of some, though weak, resistance to this strain in the children vaccinated with both vaccines.