Genetic characterisation of the influenza viruses circulating in Bulgaria during the 2019-2020 winter season.

"Declarations Conflict of interestThe authors declare they have no financial interests. Ethical approvalThis work was performed in line with The Code of Ethics of the World Medical Association (Declaration of Helsinki) for experiments involving humans. The study was approved by the Institutional Review Board/ Institutional Ethics Committee of the National Centre of Infectious and Parasitic Diseases (Number IRB 00006384). Consent to participateWritten informed consent to participate in the study was obtained from all individual participants (or parents/ legal guardians in the case of children under 16) before specimen collection and testing. Conflict of interest The authors declare they have no financial interests."

"Funding This work was supported by the Ministry of Health in Bulgaria (“National Plan of the Republic of Bulgaria for Influenza Pandemic Preparedness”) and the National Science Foundation (Project DH 13-15/20.12.2017)."