COVID-19 vaccination effectiveness in the population of Friuli Venezia Giulia, North-East Italy. Control of bias associated with divergent compliance to policies in a test-negative case-control study

• Valentina RosolenRegione Autonoma Friuli Venezia Giulia
• Federico TuroldoUniversity of Trieste
• Gianna ZamaroRegione Autonoma Friuli Venezia Giulia
• Flavio Del Bianco
• Patrizio PezzottiIstituto Superiore di Sanità
• Luigi CastriottaRegione Autonoma Friuli Venezia Giulia
• Fabio BarboneUniversity of Trieste