Inclusion Criteria:  Any individual aged 18 and older eligible to receive AZ1222 vaccine following the national immunization recommendations. Willing and able to provide informed consent.  Exclusion Criteria:  Any significant acute or chronic medical condition that in the opinion of the vaccinator makes the participant unsuitable for participation in the study or jeopardises the safety of the participant. Participant reports being pregnant. History of severe adverse reaction associated with a vaccine and/or severe allergic reaction (e.g., anaphylaxis) to any component of the vaccine.  Test negative vaccine effectiveness case-control study  The study population consists of individuals presenting at the participating hospitals and health centres during the study period, who:  Either  Are hospitalized (or died) for an illness consistent with possible COVID-19. Or (in case of other hospital controls) Presented to the emergency department (ED) for reasons other than a COVID-19 like illness (e.g. trauma or elective surgery).  And  Meet the inclusion criteria.  Inclusion criteria:  Ever eligible to receive AZ1222 vaccine following the national immunization recommendations prior to hospital admission.  And  Willing and able to provide informed consent.  Exclusion criteria:  None