METHOD FOR OBTAINING ATTENUATED STRAINS OF INFLUENZA A VIRUS - CANDIDATES FOR LIVE INFLUENZA VACCINES Russian patent published in 2018 - IPC C12N7/00 A61K39/145 

FIELD: biotechnology.

SUBSTANCE: present invention relates to method for producing attenuated strains of the influenza A virus candidate for live influenza vaccines. Method consists in inserting an attenuated amino acid substitution F658A simultaneously into the conserved portion of the COOH domain of the PA gene of the epidemic virulent strain A/WSN/33 of the influenza A virus, simultaneously with the inclusion of site-specific mutations in the PB1 gene and the PB2 gene, PB1 gene of strain A/WSN/33 includes a complex of ts mutations from the genome XA of the donor attenuation donor A/Ann Arbor/6/60 (H2N2) : K391E, E581G, E457D or one ts-mutation I147T from genome XA of attenuation donor A/Krasnodar/101/35/59 (H2N2), and as a site-specific mutation included in the PB2 gene of strain A/WSN/33, ts-mutation of V290L from the genome XA of the donor attenuation A/Krasnodar/101/35/59 (H2N2) gene is used.

EFFECT: invention allows to obtain attenuated strains of the influenza A virus that provide better immune protection than preparation of reassortants based on the standard XA donor attenuation and can be used in the medical industry.

1 cl, 5 tbl, 7 ex, 1 dwg