“…In addition, countries increased the capacity of the existing HCWF by asking staff to work extra hours and cancelling leaves of absence or planned retirements[47,52,53,59, 63, 80, 85]. Furthermore, volunteers from the general public and/or non-HCWs were also mobilized to play different roles[41,47, 76]. In addition to hiring extra HCWs using different types of contracts (volunteer, freelance, short-term, temporary and permanent), undergraduate students and HCWs in specialist training (specialties or subspecialities) [83] served as resources for support roles[49] and to provide care to COVID-19 patients[63,75], as part of a reserve list[76] or in helplines [64, 80], rapid response, case investigation, contact tracing[41, 80], and psycho-social support[41].…”