No abstract

The coronavirus disease 2019 (COVID-19) pandemic has compelled governments around the world to deploy preventive and control measures of unprecedented stringency and scale. In Hong Kong, the Chief Executive-in-Council has invoked extensive powers under Section 8 of the Prevention and Control of Disease Ordinance (Cap 599) and adopted a series of subsidiary regulations in an attempt to control the spread of COVID-19.Such extensive power is subject to judicial scrutiny using a four-stage proportionality inquiry tailored for evaluating whether rights and freedomsderogating laws and measures are consistent with the Basic Law and the Hong Kong Bill of Rights Ordinance (Cap 383). In the context of a public health emergency, it has to be shown that such laws and measures pursue legitimate aims that are required by the "exigencies of the public health situation" 1 and are rationally connected to them. They should also be no more than reasonably necessary to achieve these aims without imposing an unacceptably harsh burden upon the individual.Drawing upon the framework of the proportionality inquiry, we seek to explore the medical and constitutional justifications underlying three of such regulations: compulsory use of face masks, group gatherings ban, and compulsory testing for high-risk groups. Furthermore, we will comment on the potential mandatory use of the "LeaveHomeSafe" application in public facilities for contact tracing purposes, as well as compulsory vaccination for healthcare workers.The use of face masks in public areas has been made compulsory under the Prevention and Control of Disease (Wearing of Mask) Regulation (Cap 599I). Use of face masks in conjunction with other social distancing measures reduces the risk of transmission of coronaviruses. 2 This measure may be more useful in the current pandemic as pre-symptomatic and asymptomatic transmissions are common. 3 Moreover, several local clusters have been associated with mask-off activities. 4 In contrast with public backlash over wearing masks in other regions, Hong Kong has registered a significantly high level of selfcompliance reaching up to 97%, 5 which is attributed to lessons learnt from 2003 severe acute respiratory