Harvard University - Global Health Program, Epiconcept, Government of Albania - Institute of Public Health, Government of Albania - Institute of Public Health, Southeast European Center for Surveillance and Control of Infectious Disease, Government of Albania - Institute of Public Health, Government of Albania - Institute of Public Health, Government of Albania - Institute of Public Health, Government of Albania - Institute of Public Health, Harvard University - Global Health Program, Harvard University - Global Health Program, World Health Organization (WHO) - World Health Organization Regional Office for Europe, World Health Organization (WHO) - World Health Organization Regional Office for Europe, World Health Organization (WHO) - World Health Organization Regional Office for Europe, Charité - Universitätsmedizin Berlin - Institute of Virology, World Health Organization (WHO) - World Health Organization Regional Office for Europe, World Health Organization (WHO) - World Health Organization Regional Office for Europe, Epiconcept, Government of the United States of America - Influenza Division, World Health Organization (WHO) - World Health Organization Regional Office for Europe and Government of Albania - Institute of Public Health