[GENETIC CHARACTERISTICS OF INFLUENZA A/H3N2 AND B VIRUSES THAT HAD CIRCULATED IN RUSSIA IN 2013 - 2015]

Area of Science:

• Virology
• Genetics
• Epidemiology

Background:

• Influenza A/H3N2 and B viruses pose a significant public health threat.
• Understanding viral genetic characteristics is crucial for effective disease control.

Purpose of the Study:

• To establish genetic characteristics of influenza A/H3N2 and B viruses that circulated in Russia between 2013-2015.
• To perform phylogenetic analysis and identify molecular markers for drug resistance.

Main Methods:

• Sequencing of viral RNA from 80 influenza A/H3N2 and 31 influenza B samples.
• Utilized ABI-3100 Genetic Analyzer and MiSeq for sequencing.
• Data analysis performed using CLC, DNASTAR, and BioNumerics software.

Main Results:

• Influenza A/H3N2 strains evolved, with clade 3C.2a dominating in 2014-2015.
• Yamagata lineage predominated among influenza B viruses, with one reassortant detected.
• All influenza A/H3N2 viruses exhibited a rimantadine resistance mutation (S31N in M2 protein).
• No oseltamivir resistance mutations were detected in either influenza A/H3N2 or B viruses.

Conclusions:

• Increased influenza morbidity in 2014-2015 was linked to antigenically distinct influenza A/H3N2 and B viruses.
• The emergence of distinct influenza B lineages and reassortants supports the use of quadrivalent vaccines.
• WHO updated vaccine components for 2015-2016 due to these viral changes.