inclusion criteria: * are aged ≥18 and \<70 years old; * licenced to practice in quebec; * working or scheduled to work over the next 16 weeks in a setting at high-risk of contact with covid-19 infected individuals, particularly (but not only) those involved with aerosol generating medical procedures in hospitals and/or caring for patients in long-term care facilities; * working in high covid incidence areas; * covered by the ramq for medical services and hospitalisations; * has a personal email or phone (to which to send every two weeks a reminder and questionnaire by email or text messages); * has a fixed address (to which to send the material) in the greater montreal or surrounding areas.

inclusion criteria: * are aged ≥18 and \<70 years old; * licenced to practice in quebec; * working or scheduled to work over the next 16 weeks in a setting at high-risk of contact with covid-19 infected individuals, particularly (but not only) those involved with aerosol generating medical procedures in hospitals and/or caring for patients in long-term care facilities; * working in high covid incidence areas; * covered by the ramq for medical services and hospitalisations; * has a personal email or phone (to which to send every two weeks a reminder and questionnaire by email or text messages); * has a fixed address (to which to send the material) in the greater montreal or surrounding areas.

inclusion criteria: - are aged ≥18 and <70 years old; - licenced to practice in quebec; - working or scheduled to work over the next 16 weeks in a setting at high-risk of contact with covid-19 infected individuals, particularly (but not only) those involved with aerosol generating medical procedures in hospitals and/or caring for patients in long-term care facilities; - working in high covid incidence areas; - covered by the ramq for medical services and hospitalisations; - has a personal email or phone (to which to send every two weeks a reminder and questionnaire by email or text messages); - has a fixed address (to which to send the material) in the greater montreal or surrounding areas.

inclusion criteria: - are aged ≥18 and <70 years old; - licenced to practice in quebec; - working or scheduled to work over the next 16 weeks in a setting at high-risk of contact with covid-19 infected individuals, particularly (but not only) those involved with aerosol generating medical procedures in hospitals and/or caring for patients in long-term care facilities; - working in high covid incidence areas; - covered by the ramq for medical services and hospitalisations; - has a personal email or phone (to which to send every two weeks a reminder and questionnaire by email or text messages); - has a fixed address (to which to send the material) in the greater montreal or surrounding areas.

inclusion criteria: - are aged ≥18 and <70 years old; - licenced to practice in quebec; - working or scheduled to work over the next 16 weeks in a setting at high-risk of contact with covid-19 cases, particularly (but not only) those involved with aerosol generating medical procedures in hospitals and caring for patients with no negative pressure room (ltcf); - working in high covid incidence areas; - covered by the ramq for medical services and hospitalisations; - has a personal email or phone (to which to send every two weeks a reminder and questionnaire by email or text messages); - has a fixed address (to which to send the material) in the greater montreal or surrounding areas.

inclusion criteria: - are aged ≥18 and <70 years old; - licenced to practice in quebec; - working or scheduled to work over the next 16 weeks in a setting at high-risk of contact with covid-19 cases, particularly (but not only) those involved with aerosol generating medical procedures in hospitals and caring for patients with no negative pressure room (ltcf); - working in high covid incidence areas; - covered by the ramq for medical services and hospitalisations; - has a personal email or phone (to which to send every two weeks a reminder and questionnaire by email or text messages); - has a fixed address (to which to send the material) in the greater montreal or surrounding areas.