[High level of efficacy and safety of antiviral vaccines and unsubstantiated critique].

To counterbalance the unsubstantial declarations of some vaccinologists that vaccines and vaccination are not only useless, but also injurious to the health, this work represents the evidence that vaccines and vaccination not only reduce the morbidity of viral infection, but also allow some viral diseases to be eradicated and eliminated. The work also adduces the data about reducing economic impact of viral infections with the help of vaccination, as well as the data, which clearly show that serious reactions to vaccination are thousands of times less frequent than reactions and complications caused by infectious diseases.

[New cold-adapted donor strains for live influenza vaccine].

Cold-adapted (CA) strains A/Krasnodar/35 and B/Victoria/63 were isolated using passages of A/Krasnodar/101/59 and B/Victoria/2/87 wild type strains at low temperatures. The resulting CA strains possessed TS and CA phenotypes and had a reduced ability to reproduce in mouse lungs and nasal turbinates. They displayed a high protective efficacy in experiments on mice.

[Epidemiologic and economic effectiveness of school closure during influenza epidemics and pandemics].

Epidemiologic and economic effectiveness of school closure during influenza epidemics and pandemics is discussed. Optimal effect of school closure is observed when this measure is taken at the start of the epidemic or pandemic and for a sufficiently long time. School closure during high morbidity among schoolchildren, in the middle (at the peak) and by the end of epidemic or pandemic does not influence significantly the spread of influenza or morbidity.

[Study of immunogenicity and protective efficacy of a novel inactivated vaccine with chitosan against influenza A/H1N1/2009].

Aim: Study of immunogenicity and protective efficacy of a novel inactivated vaccine with chitosan against influenza A/H1N1/2009.

Materials And Methods: Influenza virus A/California/7/2009 (H1N1) strain was used in the study. Mice were immunized twice (21 day interval) with experimental samples of inactivated influenza vaccine: No.

[Increasing the immunogenicity of inactivated chitosan adjuvanted vaccine from A/California/7/09 (H1N1) strain and analyzing the antigenic specificity of this influenza virus strain].

Addition of chitosan as an adjuvant to subunit vaccine from the swine origin influenza virus A/California/7/09 (H1N1) increases vaccine immunogenicity by 8-16 times and significantly enhances its protective potency. Single immunization with chitosan adjuvanted vaccine induced similar antibody titers as two immunizations with unadjuvanted vaccine. Chitosan stabilized the immunogenicity of subunit vaccine when stored at 4 degrees C.

[Enhancing the immunogenicity of inactivated polio vaccines with chitosan used as an adjuvant].

Addition of chitosan to inactivated trivalent polio vaccine or inactivated preparations of attenuated poliomyelitis viruses (Sabin strains) significantly increases immunogenicity of these inactivated poliomyelitis virus preparations. High neutralizing antibody titers are detected after two immunizations of mice and a single immunization of rats, as well as when the antigen dose was reduced by 4 times. Addition of chitosan as an adjuvant significantly induces cellular immunity.

[Problem of influenza prophylaxis by vaccines].

Scientific data is presented and problems of influenza prophylaxis in various age groups are discussed. Influenza prophylaxis in neonates is possible by inducing maternal antibodies, this dictates the necessity of influenza vaccination in pregnancy. Problems of influenza prophylaxis are most pressing in the group of children from 6 months to 2 years of age.

[Live cold-adapted influenza vaccine: state-of-the-art].

The review characterizes the currently used cold-adapted donor strains of influenza virus attenuation to prepare cold-adapted reassortants with actual epidemic influenza virus strains. It considers new procedures for preparing attenuated influenza virus strains for live influenza vaccines, as well as analytical methods and the genome composition of reassortants. Recent data on the safety of live cold-adapted influenza vaccines (LCAIVs), including those on the genetic stability of vaccine reassortants and the immunogenicity and efficacy of these vaccines for different age groups, are discussed.

[Increase of immunogenicity of cold-adapted influenza vaccine by using adjuvant].

Aim: To assess increase of protective efficacy of live cold-adapted (ca) influenza vaccine after addition of adjuvant chitozan.

Materials And Methods: Used viruses: ca donor of attenuation A/Krasnodar/101/35/59 (H2N2) and epidemic strain A/Krasnodar/101/59 (H2N2); as an adjuvant--derivative of chitozan and microparticles of chitozan. Experiments were performed in outbred mice.

[Swine-origin influenza H1N1/California--passions and facts].

Analysis of pandemic caused by swine influenza virus H1N1/California showed moderate virulence of this virus compared to pandemic viruses, which caused pandemics in 1918, 1957, and 1968. During seasonal influenza epidemic in countries of southern hemisphere (June-August 2009) despite on circulation of H1N1/California strain, epidemics was caused by human influenza viruses H3N2 and H1N1. It was concluded that strain H1N1/California could not be attributed to pandemic strains of influenza viruses.

[Prevention of influenza in pregnant women and neonatal infants].

The review presents the data available in the literature on the incidence of influenza, postinfluenza complications, hospitalizations, and deaths in pregnant women, on the negative fetal and neonatal impact of this disease in pregnant women, on vaccination of pregnant women with inactivated influenza vaccines. It also gives data on the high rates of influenza complications, admissions, and death in the newborns and on possible prevention of neonatal influenza at the expense of maternal antibodies. It is concluded that it is expedient to vaccinate pregnant women against influenza to reduce the rates of morbidity, hospitalization, and mortality due to influenza infection among both women themselves and neonatal infants.

[Chitosan as an adjuvant for inactivated vaccines against avian influenza viruses].

Aim: To study chitozan as an adjuvant for inactivated vaccines against A/H5 influenza viruses.

Materials And Methods: Avian A/H5 influenza viruses were grown on chicken embryos or on MDCK cell line; viruses-containing fluid was inactivated with formalin. Mice were vaccinated intramuscularly with inactivated avian influenza virus mixed with chitozan and then levels of hemagglutination-inhibiting and neutralizing antibodies as well as protective efficacy against both homologous and drifted strains of avian influenza viruses A/H5 were measured.

[Influence of chitosan on immunophenotype and functional activity of murine mononuclear leukocytes after immunization with inactivated influenza vaccine].

In the overwhelming majority of countries inactivated vaccines, which form mainly humoral immunity, are used for prevention of influenza. The objective of the study was to assess the combined effect of inactivated influenza vaccine and chitozan on cellular immunity in CBA line mice. Intramuscular administration of 2 doses (with 4 week interval) of inactivated influenza vaccine and chitozan resulted in increased cytotoxic activity of splenic NK cells against NK-sensitive cell line K562 as well as in increased proliferative activity of mononuclear leukocytes, and numbers of CD3 T-lymphocytes, NKT cells, B-lymphocytes in animals' spleens.

[Chitosan as an adjuvant for parenteral inactivated influenza vaccines].

Addition of 0.5% chitosan derivative to parenteral inactivated influenza vaccines increased antibody titers in the single immunization of mice by 4-5 times while double immunization showed 6-to-10-fold increases as compared with immunization without chitosan. Moreover, chitosan-containing vaccines induced the generation of antibodies to the drift variants of influenza virus.

[Influenza pandemic: hypotheses and facts].

Data on influenza pandemics as well as on the characteristics of influenza viruses, which caused pandemicsin 1918, 1957, 1968, and 1977 are presented. Mechanisms of pandemic influenza virus strains evolving, including mutations resulting in increase of virulence, as well as possibility of human and avian influenza viruses reassortment process as the source of pandemic strains are discussed. Mechanisms of transformation of mildly virulent influenza virus strains to highly virulent, which can cause epizootics, are reviewed.

[Influenza vaccination of children as a general factor in prevention of influenza epidemics].

The data about high morbidity of children influenza and their hospitalization, and principle role of children in speacling of influenza are presented. Total influenza vaccination of children decrease the influenza morbidity and hospitalization of children, and also may be to decrease the influenza morbidity of nonvaccinated population whole during influenza epidemics. Problems of effective vaccination of infants are discussed and data about economic effect of their total vaccination are presented.

[Vaccines and chemicals for the prevention of influenza].

The review gives data on the reactogenicity, immunogenicity, and protective efficacy of the existing influenza vaccines, such as inactivated (conjugate, subunit, virosomal, cultural vaccines with adjuvants) and live vaccines, as well as on the new directions in the design of influenza vaccines. It also provides data on specific medications against influenza and discusses the problem associated with the occurrence of influenza viruses resistantto these drugs. The economic efficiency of the prevention of influenza with vaccines and drugs is under debate.

[Molecular mechanisms of reversions to the ts+ -phenotype of cold-adapted influenza virus A strains--attenuation donors for live influenza reassortant vaccines].

A ts+ revertant of cold-adapted (ca) strain A/Leningrad/134/47/57--the attenuation donor for live influenza reassortant vaccines--was obtained by passages of the ca strain in chick embryos at nonpermissive temperatures. The ts+ revertant acquired the ability to grow in chick embryos at 40 degrees C and lost the capacity to reproduce there at 25 degrees C. A complementation-recombination test using the fowl plague virus (FPV0 ts-mutants showed the loss of the ts-phenotype in the RNA-segments of ts+ revertants' genome coding for PB2, NP, and NS (NS2) proteins.

[Avian flu epizootia and its prevention].

In the review cited the data about avian flu epizootia for last years, about economic damage by epizootia, the information on an infection of people by viruses of animals. Problems the development of vaccines against a avian flu, including ways of designing of vaccine strains are discussed. Data on methods of struggle with avian influenza epizootia of poultry, about methods of prevention the epizootia and uses for this purpose of vaccines and drugs are resulted.

[Prevention of influenza in infants].

The review summarizes recent data on the incidence of influenza and hospital admissions for this disease among infants aged 0 to 2 years. It considers the optimal influenza prevention regimens in the age groups of 0 to 6 months and 6 months to 2 years, by using influenza vaccines for immunization of infants and all those contacting them inside and outside, as well as pregnant women. Whether prophylaxis of influenza A can be made in Russia is also discussed.

[Development and certification of libraries of the MDCK continuous cell line for production of influenza vaccine].

Seeding and working banks of the continuous MDCK cell culture suitable for the production of cultured influenza vaccine were created and deposited at liquid nitrogen temperature at the "Vector" State Research Center of Virology and Biotechnology. The MDCK cell culture was shown to have morphology typical of the discussed cell line; it does not have any alien agents and is oncogenically safe; its enzimogram and karyotype are typical of the donor line; finally, its biological properties are stable during a long period of cultivation and its sensitivity to influenza virus is high, therefore, it can be recommended for the production of influenza vaccine. The continuous MDCK cell line was certified at Tarasevich Committee and was recommended by the MIBP Committee, Russia's Health Ministry, for its use as a substrate in the production of diagnostic and preventive immunoglobulins.

[Further development (MDCK) of live cold-adapted influenza vaccine: cultivation of vaccine strains in production fermenters].

Optimal conditions were developed for cultivating the cold-adapted reassortant live influenza vaccine (CARLIV) in MDCK cells, which were in their turn cultivated in fermenters with serum-free medium and microcarrier. The use of MDCK cells meets all national and WHO requirements to continuous cells used in the production of biological preparations. CARLIV cultivated under such conditions well preserve their ts-mutations and mutation, which entail substitutions of amino acids, in all CARLIV genome segments.

[Total immunization of children against influenza decreases morbidity in a number of diseases among elderly persons during influenza epidemic].

Immunization of children aged 3-6 years in kindergartens and school children aged 7-17 years against influenza with inactivated influenza vaccine was carried out in two districts of the Moscow region. The comparison of morbidity in influenza-like diseases among the immunized children with that among nonimmunized children in control districts revealed that the effectiveness of immunization was 60.9% in kindergartens and 68.

[Specific prophylaxis of influenza with inactivated split vaccine Vaxigrip].

Influenza remains a serious health problem, annually causing epidemics embracing up to 10% of the population of the world, and at the periods of pandemics this number may rise 4- to 6-fold. In the overwhelming majority of the countries the prophylaxis of influenza is carried out at present out with the use of inactivated vaccines. One of such vaccines is the highly purified split vaccine Vaxigrip (Aventis-Pasteur, France), permitted for use in Russia since 1992.

[Advantages and disadvantages of inactivated and live influenza vaccine].

Published data related with comparison studies of safety, efficiency and some other properties of cold-adapted live influenza vaccine (LIV) and of inactivated influenza vaccine (IIV) are analyzed. LIV and IIV do not differ by systemic reactions after administration; however, it is not ruled out that there can be unfavorable reactions in vaccination of persons with allergy to the chicken-embryo proteins as well as in cases of persistence/reversion of cold-adapted strain observed in vaccination of persons with primary impairments of the immune system. There are no convincing data, up to now, on that LIV is superior to IIV in coping with influenza pandemics.