RESUMO
The reassortant vaccine strain of live attenuated influenza vaccine inherits temperature sensitivity and areactogenicity from cold-adapted attenuated master donor virus. In Russia, B/ USSR/60/69 master donor virus (B60) is currently in use for the preparation of live attenuated type B influenza vaccine candidates. Trivalent live attenuated influenza vaccine based on A/ Leningrad/134/17/57 and B60 are licensed for the use in Russia for single dose vaccination of adults and children over 3 years. B/Leningrad/14/17/55 (B14) cold-adapted virus is a backup master donor virus for live attenuated type B influenza vaccine. According to our preliminary estimates, it is more attenuated than B60, which can allow expanding applicability of this vaccine for children under 3 years of age. In this paper, the role of B14 genes in its attenuation was assessed. Representative collection of reassortants of B14 with epidemic influenza B viruses was obtained, a phenotypic analysis of reassortants was performed, and their pathogenicity for animals was assessed. The leading role of PB2 and PA genes in attenuation of B14 master donor virus was proven.
Assuntos
Adaptação Fisiológica/genética , Temperatura Baixa , Genes Virais/fisiologia , Vírus da Influenza B/genética , Vacinas Atenuadas/genética , Animais , Embrião de Galinha , Estudos de Associação Genética , Humanos , Vírus da Influenza B/patogenicidade , Vírus da Influenza B/fisiologia , Vacinas contra Influenza/genética , Vacinas contra Influenza/uso terapêutico , Influenza Humana/prevenção & controle , Camundongos , Fenótipo , Federação Russa , Temperatura , Replicação Viral/genéticaRESUMO
We studied the constellation of genes encoding polymerase complex proteins of master donor viruses for Russian live attenuated influenza vaccine type B. Reassortants of the reserve attenuation donor B/Leningrad/14/17/55 with B/USSR/60/69 master donor virus currently used for manufacturing seasonal influenza vaccine were prepared and examined. Most reassortants obtained by the classical reassortment method inherited all genes from the B/Leningrad/14/17/55 virus except the gene encoding PB1 subunit of the polymerase complex. One reassortant was selected for further evaluation of the role of PB1 gene. Greater attenuation of the strain for experimental animals (mice) in comparison with the original strains was demonstrated. This indicates high degree of constellation of genes of cold-adapted master donor viruses and the important compensating role of amino acid substitutions in the PB1 protein of B/Leningrad/14/17/55 donor virus in preventing viral hyperattenuation.
Assuntos
Betainfluenzavirus/genética , Influenza Humana/prevenção & controle , Proteínas Virais/genética , Substituição de Aminoácidos/genética , Animais , Embrião de Galinha , Temperatura Baixa , Humanos , Vacinas contra Influenza/imunologia , Betainfluenzavirus/imunologia , Camundongos , Vírus Reordenados/genética , Vírus Reordenados/imunologia , Vacinas Atenuadas/imunologiaRESUMO
We developed a pyrosequencing protocol for monitoring of stability of attenuating mutations in the genome of vaccine reassortants based on master donor virus of Russian live attenuated influenza vaccine B/USSR/60/69. The developed protocol allows rapid and accurate assessment of mutations and can be used for analysis of genetic stability of reassortants during vaccine strain development and manufacturing, as well as genetic stability of vaccine isolates of influenza B virus during pre-clinical and clinical trials.
Assuntos
Análise Mutacional de DNA/métodos , Instabilidade Genômica , Vacinas contra Influenza/genética , Análise de Sequência de DNA/métodos , Vacinas Atenuadas/genética , Animais , Embrião de Galinha , DNA Viral/análise , Humanos , Vacinas contra Influenza/análise , Influenza Humana/prevenção & controle , Tipagem Molecular/métodos , Vacinas Atenuadas/análise , Virologia/métodosRESUMO
In 16 hypertensive patients levels of glucose, immunoreactive insulin and C-peptide were studied during oral glucose tolerance test before and 10 days after treatment with captopril. The analysis of the results obtained showed that captopril had no effect on carbohydrate metabolism which is advantageous for treatment of hypertensive patients.