[The antigenic structure of influenza B viruses isolated in 1991]. / Antigennaia struktura virusov grippa B, vydelennykh v 1991 g.

A comparative immunological analysis of the antigenic structure of reference influenza B viruses of 1940-1984 and isolates of 1986-1991 using monospecific antibodies to individual antigenic determinants and monoclonal antibodies to hemagglutinin of B/Oregon/5/80 virus demonstrated a further antigenic drift of influenza B viruses from the reference variants B/Victoria/2/87 and B/Yamagata/16/88. Alongside with circulation of viruses with new antigenic properties, variants were found in the epidemic outbreak of 1991 whose hemagglutinin had common antigenic markers with those of variants of the previous years.

[The characteristics of the epidemic strains of the influenza B viruses that caused the 1990-1991 epidemic in the USSR]. / Kharakteristika épidemicheskikh shtammov virusov grippa B, vyzvavshikh épidemiiu 1990--1991 gg. v SSSR.

Epidemics of influenza in towns of Russia were found to have been caused by influenza type B virus. Strains similar to B/Yamagata/16/88 were first isolated in the country. The study of antigenic and biological properties showed that the epidemic strains could be divided into 2 groups: similar to B/Victoria/2/87 and to B/Yamagata/16/88, that is, representing two branches of the evolutionary tree. In both groups the viruses were heterogeneous both in antigenic and biological properties.

[The antigenic and biological properties of influenza A (H1N1) viruses isolated in the USSR and the Czechoslovak Federal Republic in 1988-1989]. / Izuchenie antigennykh i biologicheskikh svoistv virusov grippa A (h1N1), izolirovannykh v SSSR i ChSFR v 1988--1989 gg.

A comparative study of influenza A (H1N1) virus strains isolated in one epidemic season (1988-1989) in neighbouring countries was carried out. Using polyclonal and monoclonal antibodies, some of the isolates were shown to have different antigenic and biological properties which probably determined the different intensity of the epidemic situation in the USSR and CzSFR in 1988-1989.

[The characteristics of influenza A/H1N1 viruses related to A/PR/8/34 isolated in the Mongolian People's Republic]. / Kharakteristika virusov grippa A/H1N1, rodstvennykh A/PR/8/34, izolirovannykh v MNR.

Investigations of the antigenic structure and genome of influenza A (H1N1) viruses isolated in the Mongolian People's Republic in 1982, 1983, 1986 and 1987 from children with acute respiratory diseases using monoclonal antibodies and nucleotide sequencing revealed 4 strains identical to the prototype strain A/PR/8/34 (H1N1), variant M. Sinai, and 8 strains closely similar to the epidemic strain A/USSR/90/77 (H1N1) in the antigenic structure and A/Leningrad/54 (H1N1) in the primary structure of HA.

[Influenza viruses studied by fluorescent immunoassay with temporary resolution]. / Issledovanie virusov grippa metodom fliuorestsentnogo immunoanaliza s vremennym razresheniem.

Monoclonal antibodies, epidemic strains of influenza A and B viruses, conjugates were studied by fluorescence immunoassay with temporary resolution using equipment of different companies. Differences and specificity of monoclonal antibodies to influenza A and B viruses were demonstrated. The highest sensitivity of the method with the test system used was determined, being 20 ng/ml of viral protein. The method was shown to be useful for influenza virus detection both in solutions containing purified virions and in virus-containing allantoic preparations. It was established that virological studies could be carried out using conjugates and knock-down microplates of the national make alongside with foreign ones.

[A comparative analysis of epidemic strains of the influenza A virus (H1N1), isolated in the USSR and Czechoslovakia in 1986]. / Sravnitel'nyi analiz épidemicheskikh shtammov virusa grippa A (H1N1)izolirovannykh v SSSR i ChSSR v 1986 g.

A comparative study of antigenic and molecular-biological properties of epidemic influenza virus strains isolated in the USSR and CSSR in the autumn-winter, 1986-1987 was carried out and showed that the epidemics in both countries were due to influenza A viruses of H1N1 subtype, antigenically related to the reference A/Taiwan/1/86 and A/Singapore/6/86 strains, which was confirmed by electrophoretic studies. The strains were found to vary in sensitivity to heating and to the inhibitors.

[The primary structure of the hemagglutinin of influenza A (H3N2) viruses isolated in the USSR in 1985]. / Pervichnaia struktura gemaggliutinina virusov grippa A (H3N2), izolirovannykh v SSSR v 1985 g.

The primary structure of hemagglutinin of the members of three main antigenic groups of current influenza A (H3N2) viruses was determined. A phenomenon of "antigenic mimicry" was found to be due to the accumulation of reversions in hemagglutinin structure at late stages of antigenic drift.

[Antigenic drift of epidemic strains of influenza A virus (H3N2) in 1985]. / Antigennyi dreif épidemicheskikh shtammov virusa grippa A (H3N2) 1985.

The study included 230 strains of influenza A (H3N2) virus isolated in the epidemic of 1985. A high degree of heterogeneity of the virus population was established with polyclonal sera, monoclonal antibodies and the method of kRNA-bRNA hybridization for the determination of the genome composition. Among the strains of one epidemic (1985) three antigenically heterogenous groups of strains were detected similar with reference A/Philippines/2/82, A/Ken/1/84, and A/Mississippi/1/85 strains. It was shown that in the process of antigenic drift in some strains there occurred a reversion of the antigenic determinants similar to those of previously circulating epidemic A/Texas/1/77 strain.

[Antigenic and biological characteristics of strains of the influenza A (H3N2) virus, similar to virus A/Hong Kong/68, isolated from children in the USSR in 1986]. / Antigennye i biologicheskie kharakteristiki shtammov virusa grippa A (H3N2), podobnykh virusu A/Gonkong/68, izolirovannykh ot detei v SSSR v 1986 g.

Influenza A viruses (H3N2) isolated in the USSR, 1986, from children were antigenically similar to the prototype A/Hong Kong/1/68 strain. Alongside with the similarity with the latter virus, the new isolates had a number of distinctive features both in the antigenic specificity of hemagglutinin and in the structure of the polymerase complex proteins. All the foregoing allows to exclude laboratory contamination and suggests the possibility of circulation of such viruses among children.

[Antigenic and biological characteristics of influenza virus A strains isolated in 1985]. / Antigennye i biologicheskie osobennosti shtammov virusa grippa A, izolirovannykh v 1985 g.

The antigenic structure of hemagglutinin of influenza A virus (H3N2) strains isolated in 1985 was studied using a series of monoclonal antibody to A/Dunedin/4/73/A (H3N2) and A/Bangkok/1/79/A (H3N2), and biological and physico-chemical properties of these strains were compared with those of influenza A (H3N2) virus of 1983 and reference A (H3N2) of 1979-1984 (the rate of adsorption on chick erythrocytes and eluting activity, thermostability of hemagglutinin and neuraminidase, sensitivity to nonionic detergents, sensitivity to remantadine, analysis of virion polypeptide composition). A high degree of heterogeneity of the 1985 strain population of influenza A (H3N2) virus was revealed both in the antigenic structure of hemagglutinin and in all the biological and physico-chemical parameters tested. It was suggested that the A/Caen/1/84 strain originated not from A/Philippines/2/82 but directly from A/Texas/1/77.

[Antigenic specificity of the neuraminidases of epidemic strains of influenza A/H3N2 viruses circulating in the USSR 1983-1985]. / Antigennaia spetsifichnost' neiraminidaz épidemicheskikh shtammov virusov grippa A/H3N2, tsirkulirovavshikh v SSSR v 1983-1985 gg.

The antigenic properties of neuraminidase of the epidemic strains of 1983-1985 were studied by means of lectin test and thiobarbituric method using polyclonal sera and monoclonal antibody. Populations of the viruses with respect to antigenic relationships of neuraminidase were shown to be heterogeneous. A considerable portion of the strains occurring in 1985 underwent antigenic drift from the reference A/Philippines/2/82 strain. The epidemic novelty of some strains was due to changes in only one supercapsid protein-neuraminidase.

[Analysis of the antigenic specificity of the neuraminidases of influenza B viruses isolated in different years]. / Analiz antigennoi spetsifichnosti neiraminidaz virusov grippa B, izolirovannykh v raznye gody.

The antigenic structure of neuraminidases of influenza B viruses isolated in 1940-1984 was studied. Lectin test has first been employed for analysis of influenza B virus neuraminidase. The antigenic composition of neuraminidases of these viruses was shown to be different. The strains isolated in the epidemic of 1983-1984 underwent further drift of the neuraminidase component and represent a heterogeneous group in this respect. The use of monospecific antiserum to purified neuraminidase helped specify antigenic relationships of this protein.

[Physiochemical properties of purified and virion neuraminidases of the influenza B viruses]. / Fiziko-khimicheskie svoistva ochishchennykh i virionnykh neiraminidaz virusov grippa B.

A method for isolation of neuraminidase using pronase has been developed. Purified preparations have been recovered from two influenza B virus strains, B/Mass/3/66 and B/USSR/14/80. Physico-chemical properties of neuraminidases were compared; optimal conditions for the determination of neuraminidase activity of these strains were determined. Strains differences in thermostability, optimal pH, specificity to substrates were established. Neuraminidases, isolated or present in virions, were shown to be identical in enzymatic characteristics but to differ in thermostability.

[Analysis of the influenza situation in the USSR and the GDR in nonepidemic (1978-1979) and epidemic (1979-1980) seasons]. / Analiz situatsii po grippu v SSSR i GDR v neépidemicheskii (1978-1979 gg.) i épidemicheskii (1979-1980 gg.) sezony.

Analysis of comparative surveillance on influenza carried out in the USSR and the GDR is presented. It was shown that both in the nonepidemic and epidemic seasons the incidence of influenza in the USSR increased considerably earlier than in the GDR. In the nonepidemic season of 1978-1979, strains of different antigenic structure were in circulation in the USSR and the GDR, whereas the epidemic of 1979-1980 was induced by new drift variants of A(H3N2) virus, A/Bangkok/1/79 and A/Bangkok/2/79. The epidemic strains circulating in both countries were dissimilar biologically and antigenically. In the nonepidemic period in the USSR and GDR the circulating A(H1N1) strains were represented not only by drift variants A/USSR/90/77 and A/Brazil/11/78 but also by natural recombinants of A(H1N1), A/USSR/61/79, in which the internal proteins (P, NP, NS, and M) were analogous to those of A(H3N2).

[Radioimmunological study of the antigenic conformity of the hemagglutinins of vaccinal and epidemic strains of influenza virus]. / Izuchenie radioimmunologicheskim metodom antigennogo sootvetstviia gemaggliutininov vaktsinnykh i épidemicheskikh shtammov virusa grippa.

Antigenic relationships of the vaccine A/Victoria/35/72 strain and vaccine candidate A/Khabarovsk/15/76 and recombinant RK-5 strains with hemagglutinins of the epidemic A/Victoria/3/75, A/Leningrad/173/75, and A/Victoria/112/76 strains were studied by radioimmunoassay (RIA) in two test systems. Alongside with other tests RIA is useful and expedient for rapid and accurate quantitative evaluation of the antigenic conformity of influenza virus strains under comparison.

[Heterogeneity of monospecific antibodies to the hemagglutinin of influenza virus H3N2 studied by radioimmunological analysis]. / Izuchenie geterogennosti monospetsificheskikh antitel k gemaggliutininu virusa grippa H3N2 metodom radioimmunologicheskogo analiza.

Heterogeneity of antibodies against influenza virus hemagglutinin has been confirmed. Various subpopulations of antibodies to the A/Khabarovsk/15/76 hemagglutinin were demonstrated some of which showed greater affinity to MRC-11 hemagglutinin than to the HA of the strain inducing this antibody synthesis. Apparently subpopulations of antibodies with low affinity to their "own" epitopes in the hemagglutinin-immunogen may develop which, however, may show a sufficiently high affinity to these epitopes in hemagglutinins of other strains.