[The immunogenic properties and prophylactic efficacy of a live polyvalent influenza vaccine in children 5 to 14 years old]. / Izuchenie immunogennykh svoistv i profilakticheskoi éffektivnosti zhivoi grippoznoi polivalentnoi vaktsiny u detei 5--14 let.

Production lots of a live influenza vaccine made of strains A/47/T (N1H1), A/47/6/2 (H3N2), and B/60/32 were used for vaccination of 3663 children aged from 5 to 14 years inoculated twice with monovaccines, a trivaccine made of the above strains, or placebo. Both mono- and polyvaccine were practically areactogenic. An average per cent of subjects with a significant rise in antibody titres to the respective three antigens was 60%. The efficacy of the vaccination was 31.0-42.8% for monopreparations and 36.3% for the trivaccine. The studies showed the possibility and expedience of using for children the live influenza vaccine in the form of a polyvalent preparation including current influenza type A and B viruses.

[Role of individual genes in expression of phenotypic properties of the cold-adapted strain A/Leningrad/134/47/57 (H2N2)-a donor of attenuation of live influenza vaccine]. / Rol' otdel'nykh genov v proiavlenii fenotipicheskikh svoistv kholodoadaptirovannogo shtamma A/Leningrad/134/47/57 (H2N2)-- donora attenuatsii zhivykh grippoznykh vaktsin.

The influenza A/Leningrad/134/47/57 (H2N2) (A/Len/47) cold-adapted virus expresses the ability to reproduce at 25 degrees C (the ca phenotype) and inability to reproduce at 40 degrees C (the ts phenotype). It was attenuated for mice. Reassortants of this donor virus with the genes coding for the surface glycoproteins from the epidemic viruses, i.e. hemagglutinin (HA) and neuraminidase (NA), have been shown to be attenuated, immunogenic and genetically stable. We made attempts to reveal the influence of individual genes from the A/Len/47 ca virus on the expression of some phenotypic properties. Different "single-gene" reassortants were created and investigated using the influenza A/PR/8/34 (H1N1) virus as another parent with the opposite phenotypic properties, i.e. lack of ca+ and ts+ phenotypes and high virulence for mice. We managed to obtain "single-gene" reassortants with PB1, NA and NS genes at this stage of the work. None of them (probably including the M gene as well) could determine the ca or ts phenotypes, nor could the presence of the NA and NS genes from the strain A/Len/47 influence these properties. However, our findings show that the combined influence (synergism) of the PB1 and NS genes from the ca donors results in the ts phenotype of the reassortants. Significant role of the NS gene for attenuation of influenza viruses in mice has been revealed.

[The reproduction of reassortant influenza A and B viruses with a known genome composition in different cell systems]. / Reproduktsiia reassortantov virusov grippa A i B s izvestnym sostavom genoma v razlichnykh kletochnykh sistemakh.

Reproduction of parental strains and reassortants (with known genome composition) of influenza A and B viruses was studied in chick embryos (CE) and in different cell lines (SPEV, MDCK, BHK-21, M22, etc.). The results agree with the concept that the yield of influenza A virus in CE depends on its M-gene. At the same time, the experimental results suggest that reproduction of influenza B virus in the same system is not determined by M-gene. Reproduction (hr-phenotype) of influenza A and B viruses in cell cultures was shown to be determined not only by the gene coding for hemagglutinin but also by other virus genes, the reproduction level being dependent on different genes in different cell systems.

[The effect of amplifying reproduction of influenza virus in mouse lungs during simultaneous infection with two cold-adapted strains]. / Effekt usileniia reproduktsii virusa grippa v legkikh myshei pri odnobremennom infitsirovanii dvumia kholodoadaptirovannymi shtammami.

Reproduction of cold-adapted (ca) strains of influenza virus in the lungs of white mice after separate and combined inoculation and the properties of isolates derived from the infected animals were studied. It was shown that after combined inoculation with ca and ts strains A/Leningrad/134/17/57 (H2N2) and A/PR/8/59/1 (H1N1) ca recombinants could develop loosing some ts mutations and possessing (unlike the master strains) pneumo-virulence for mice. All the pneumo-virulent reassortants inherited hemagglutinin from the ca A/PR/8/59/1 strain and PB1 protein from the ca A/Leningrad/134/17/57 strain. The results indicate that it is unsafe to construct live recombinant divaccines by combining the recombinants produced from different donors of attenuation.

[Molecular genetic analysis of a cold-adapted donor attenuation strain for a pediatric liver influenza vaccine, of recombinants based on it and of isolates from vaccinated children]. / Molekuliarno-geneticheskii analiz kholodoadaptirovannogo shtamma-donora attenuatsii dlia detskogo zhivoi grippoznoi vaktsiny, poluchennykh.

The recombination test demonstrated that in the genome of a highly attenuated cold-adapted variant of influenza A/Leningrad/134/47/57 virus five genes coding for nonglycosylated proteins (1, 2, 5, 7, 8) carried ts mutations. Hybridization of this variant with epidemically important strains of influenza H1N1 and H3N2 viruses produced recombinants which inherited hemagglutinin and neuraminidase from the epidemic strains and 5 (H1N1) and 6 (H3N2) genes coding for nonglycosylated proteins from the cold-adapted variant. The genomes of both recombinants were found to contain five genes coding for nonglycosylated proteins which carried ts mutations. High genetic stability of cold-adapted recombinant vaccine strains was established in immunized children.

[Photosensitizing effect of 8-methoxypsoralen on bacteriophage cd]. / Fotosensibiliziruiushchee deistvie 8-metoksipsoralena na bakteriofag cd.

Mutagenesis in extracellular phage sd by 8-metoxypsoralen (8-MOP) and longwave (lambda greater than 310 nm) UV-irradiation has been established. The kinetics of lethal and mutagenic effects of 8-MOP+light was studied. The efficiency of mutagenesis on the first linear part of mutation curve was 0.3% per the lethal hit which is 2 times lower than that of shortwave (lambda=254 nm) UV-irradiation. The maximum yield of mutants makes up 1%, after which the mutation curve is maintained. It has been established that the main (may be the only) contribution into mutagenesis is made by monoadducts, whereas the lethal effect is conditioned by diadducts (cross-links). The comparison of the efficiency of mutagenic effects of 8-MOP+light with mutagenic effects of other kinds of irradiations was carried out. The possibility of repair of damaged 8-MOP+light phage sd DNA by transfection of Escherichia coli C (uvr+) and Cs (uvr-) lysozyme spheroplasts has been established. The repair mechanism of photodamage in intact phage sd induced with 8-MOP+light was also investigated using the method of two-step irradiation. It has been shown that 65% of photodamages are repaired in E. coli SK cells in the M9 medium, i. e. under cellular metabolism. The recovery of phage sd is completely inhibited in phosphate buffer. Unlike chloramphenicol (150 microgram/ml), 1% caffeine blocks the phage recovery only by 30%. The participation of phage sd determining enzymes in its intracellular recovery from 8-MOP+light damages is assumed.

[Reparation of UV-damaged bacteriophage ed]. / Reparatsiia UF-povrezhdenii bakteriofaga ed.

A repair of UV-damaged phage DNA in the "phage-host" system in accordance with the excision reparative mechanism is demonstrated by means of centrifugation in alkaline sucrose gradient of virulent 3H-thymidine labelled phage sd. The increase of the transfectants quantity of UV-irradiated DNA on uvr+ bacteria compatibly to uvr- bacteria evidences that the bacterial host participates in phage reparation. Caffeine inhibition of UV-irradiated phage sd survival confirms the participation of cell-host in reparation of UV-damaged phage.