From SARS to COVID-19: the role of experience and experts in Hong Kong's initial policy response to an emerging pandemic

In the earliest days of 2020, news stories from Wuhan about an emerging virus outbreak sparked discussion and concern among the residents of Hong Kong (Leung and Chan, 2020). This viral outbreak coincided with a political outbreak characterized by large-scale protests and social division since June 2019 (McLaughlin, 2020). Wuhan, the epicentre of the disease known as COVID-19, caused by the novel SARS-CoV-2 coronavirus, was a short high-speed rail ride away from Hong Kong. By Chinese New Year, which was 3 weeks after the first confirmed cases, Wuhan and other parts of Mainland China were in lockdown, and it was clear that COVID-19 would disrupt daily life for the Hong Kong locals. As the threatening evolution from sporadic outbreaks to a widespread epidemic was appearing serious and imminent, both the government and the public were preparing to respond. By the third week of January, the Hong Kong Special Administrative Region's (HKSAR) government had activated its anti-epidemic response plans. Concurrently, the people of Hong Kong—who still had deep memories of the severe acute respiratory syndrome (SARS) epidemic in 2003—responded promptly and willingly with high rates of voluntary masking, hand-washing, social distancing, and the use of thermometers at the entrance of many public spaces (Chow, 2020). Despite the implementation of such containment strategies, the virus slipped through the borders and spread across continents to become a global pandemic. Many local residents felt that the government had missed opportunities to make swifter and better decisions, such as the delayed decision to close the border with the neighbouring Mainland China (Wu, 2020). However, Hong Kong weathered 2020 as one of the better-performing territories, despite its status as Asia's hub for international travel and trade (Yuen et al., 2021). As of 31 December 2020, Hong Kong had logged 8846 confirmed cases and 148 deaths, in a city of ~7.5 million people—1.37 million of whom were over 65, the age group with the highest mortality rate (Ritchie et al., 2022; see Supplementary Information Appendix 1 for case figures). Hong Kong had managed to keep the rate of infection low without ever resorting to full, formal lockdowns. Instead, the government had implemented a series of policies, including travel restrictions, testing and contact tracing, quarantines and isolations, school closures, restrictions on public gatherings and public activities (including dining hours), and mask-wearing mandates (Chan et al., 2021). Some of these policies were eagerly accepted, while others resulted in controversy, resistance, and non-compliance. Through it all, the government's announcements were accompanied by advice and comments from a variety of advisory committees and scientific experts who make up Hong Kong's science advisory system for COVID-19. Hong Kong's COVID-19 science advisory system and its pandemic responses should be understood with special consideration of two contextual perspectives: historical and political. The first case of SARS, a highly infectious and life-threatening viral respiratory disease, first appeared in Southern China in November 2002 and subsequently appeared in Hong Kong in February 2003 (World Health Organization, 2022). The virus caused patients to exhibit major clinical features such as persistent fever, malaise, chills, and dry cough (Hui et al., 2003), yet, clinicians had no experience in or effective treatment options to eliminating the virus beyond symptomatic relief and immunological support (Stockman et al., 2006). The virus spread beyond Mainland China and Hong Kong's borders via international travels to 29 countries and territories, reaching Taiwan, Singapore, Canada and Australia, though most cases remained within Asia (Chan-Yeung and Xu, 2003). Owing to the virus's short incubation period of 2–10 days and high case fatality rate of up to 12% (Sampathkumar et al., 2003)—characteristics that allowed for early detection and isolation and therefore the severance of community transmission chains—the SARS epidemic had largely subsided by June 2003 after bringing a total of 8096 cases and 774 deaths worldwide (World Health Organization, 2015), short of evolving into an out-of-control, fully fledged global pandemic like COVID-19. In the wake of SARS crossing the borders into Hong Kong, local officials instituted a series of public health reforms, including the formation of the Center for Health Protection (CHP; Hospital Authority Ordinance, 1997). The CHP comprises a number of standing expert committees, and has been developing response plans and conducting cross-government drills, all designed to improve the ability of Hong Kong to respond to health emergencies, including novel epidemics and pandemics (Center for Health Protection, 2005). This system led by CHP was in place and activated early in 2020 in response to COVID-19. The population's collective memory of SARS also positively impacted their understanding of and response to COVID-19; people were well accustomed to wearing masks, and public schools were experienced in closing for short periods in previous years with disruptive influenza outbreaks (Cowling et al., 2020). They had largely respected—and in some cases, enthusiastically embraced—mask-wearing, hand-washing, and other official and unofficial rules and norms to support social distancing and other preventative measures. The second perspective to examine is the local political context and circumstances, which went on to determine the overall acceptance by and cooperation among the Hong Kong public, despite the pre-learned behaviours from SARS. In 1984, the Chinese and British governments signed the Sino-British Joint Declaration, an international treaty, which outlined the mutually agreed terms of the 'handover' of sovereignty from the United Kingdom to China in 1997. The Joint Declaration also declares the 'one country, two systems' principle, along with the Basic Law (Hong Kong's constitutional document) both stipulating that Hong Kong's economic system and social way of life would be unchanged for fifty years until 2047 (HKSAR Government, 2021a). The Basic Law designates a system of governance led by the Chief Executive and an Executive Council. Before the Chief Executive makes important policy decisions or introduces bills and budgets to the legislature, he or she shall consult the Executive Council—whose 32 members are appointed by the Chief Executive—except when adopting certain measures in emergencies. Separately, the Legislative Council (LegCo) is the elected law-making body, who, on top of law-making duties, debate, scrutinise, and vote on budgets and laws, including those proposed by the Chief Executive. The rest of HKSAR's civil service conducts the administrative and executive functions of the government and employs 4.4 per cent of Hong Kong's workforce (174,900 people), spanning 13 policy bureaux and 56 departments (HKSAR Government, 2021b). Ever since the handover in 1997, Hong Kong people have regularly protested against various proposals to alter their freedoms and rights. A demonstration in 2003 protested the decline in freedom of speech (said to be limited by the enactment of the Article 23 of the Basic Law, which would create Hong Kong's own national security law) and the 'Occupy' movement in 2014 protested the 'brainwashing' of values (said to be caused by a proposed "national education" system; Gunia, 2019). In June 2019, the Hong Kong government was due to pass the Fugitive Offenders and Mutual Legal Assistance in Criminal Matters Legislation (Amendment) Bill 2019 (more commonly known as the "extradition bill"), which would allow extradition of criminals to Mainland China. This triggered widespread protests in fear that this bill would undermine judicial independence and violate the freedoms that Hong Kong had enjoyed thus far (BBC, 2019). At the height of the movement, almost two million people (~25% of Hong Kong's population) reportedly marched on the streets (SCMP Reporters, 2019) calling for the withdrawal of the extradition bill, the implementation of universal suffrage, as promised in the Basic Law, and the stepping down of Chief Executive Carrie Lam, among other demands. After months of clashes with pro-Beijing government officials, legislators, and a hardline police force, trust in government hit an all-time low. A survey conducted in February 2020 by Hong Kong Public Opinion Research Institute (2020) revealed that trust in the HKSAR government had fallen to 14%, while distrust in the government rose to an all-time high of 76%. The proposed bill itself, accompanied by the government's strong responses to the protests, have caused extreme polarisation of political ideologies; one side continued to call for electoral reform and democratic rights, while the other supported the government and police in using authority to ensure economic and social stability (Shen and Yu, 2021). This months-long crisis, just months prior to the beginning of the COVID-19 pandemic, had created a political 'new normal' for Hong Kong that involved record low levels of public trust in the government and the politicisation of policies that were relatively apolitical, and underpinned how COVID-19 policies would be proposed, implemented or accepted (Hartley and Jarvis, 2020). This later proved to be a challenge for the Hong Kong government when implementing more stringent and controversial anti-epidemic policies in the year 2020.

Science advice during crises. Theoretically, policy responses to pandemics can be seen as a response to an emerging crisis. From the literature of crisis management, a crisis can be defined as an event during which an urgent threat to the structures, core values and functions of a system—as perceived and experienced by a government, organisations, communities and the wider population—requires making vital decisions under conditions of time pressure and high uncertainty (Rosenthal and Kouzmin, 1997; Rosenthal et al., 2001; Boin and 't Hart, 2007). The "context of the disaster" can occasionally be defined and determined, too, by the mass media and its narratives (Rosenthal et al., 2001). While having a narrow, exclusionary definition of a 'crisis' is unproductive for theoretical development (Pursiainen, 2022), in reality, most would agree to characterise SARS and COVID-19 as a crisis requiring critical crisis management and crisis communication (Wodak, 2021). Definitionally, these pandemics threatened core values (e.g., safety, security, health, fairness), created a sense of urgency (e.g., due to the need to swiftly isolate the infected and stop transmission chains) and exhibited a high degree of uncertainty (e.g., in transmission, symptoms, treatment and mutated variants; 't Hart and Tummers (2019)). Specifically, the pandemics encompassed two types of crises using 't Hart's (2014) typology: a situational crisis, where disruptive and unexpected incidents occur 'out there' (e.g., the virus spreading in the community, healthcare systems in burden), and an institutional crisis, where the problem lies in ineffective governments, inefficient organisations or politicised policies. While these types of crisis can exist in silo, each type of crisis can trigger the other type; for instance, an unaddressed situational crisis could 'metastasise' into a serious institutional crisis (Petridou et al., 2020). How does crisis management materialise as a form of policymaking? Pandemic response can be viewed in the perspective of the crisis management cycle posited by Drennan et al. (2014). Prior to SARS or COVID-19, public health systems would be in the preparation phase, conducting simulations, training and contingency planning, based on past experiences. As a novel coronavirus emerges, the government and public health agencies would begin the response phase, mobilising operational resources to community workers and hospital managers and financial resources to hard-hit industries and low-income or disadvantaged communities. Drawing parallels to policy learning literature, crises open 'policy windows' (Kingdon, 1984) that provide opportunities for change and to overcome governmental inertia that often inhibits policy learning under 'normal' conditions (Stern, 1997). As the pandemic (or each wave) subsides, the multiple agencies can buy time in the recovery phase to debrief, rebuild, enquire and learn valuable lessons for future policymaking (Moynihan, 2008). With this, prevention efforts can take place, such as threat assessment and mitigation strategising, before embarking on preparatory work again. Specific to the Hong Kong context, SARS triggered a strong crisis management cycle to begin at the response phase with little prior preparation, given how deadly, unprecedented and unexpected the epidemic was (Lee, 2003). After SARS, the recovery phase with adequate policy learning occurred for the ensuing months and years, with multiple independent reviews and scholarly evaluations (Lee, 2003). This recovery phase also consolidated the public's vivid and emotional memories of SARS into lasting public health knowledge and health-seeking behaviours (Lau et al., 2005). The evaluations led to new prevention measures to be taken that subsequently helped to prepare for the epidemics that followed, including avian flu and swine flu. These mild outbreaks occasionally triggered only a minor activation of the crisis management cycle—that is, until COVID-19 hit suddenly, triggering an unprecedented origination of the crisis management cycle once again. The lingering and less deadly nature of COVID-19 also bought scientists and policy-makers time for more hindsight evaluation, research, policy trial-and-error and foresight for supportive measures. Ultimately, the effectiveness of the relevant policy responses depends largely on whether crisis leadership was exerted; that is, did those with crisis management responsibilities fulfil all the expected and required tasks to facilitate an effective response? Some of these key tasks inherent in successful crisis leadership were characterised by Boin et al. (2013) as sensemaking of the nature of the crisis (the pandemic), orchestrating coordination among organisations (governmental departments and public health agencies), communicating with citizens and cooperative organisations (via the media, appointed experts and industry associations) and honing their own capacity to learn from failure (gathering feedback from social distancing measures). Scholars also suggest that inter-agency tensions may yield positive outcomes, such as counteracting 'groupthink tendencies' and promoting openness (Rosenthal et al., 1991). Under the lens of crisis management, the case of Hong Kong's pandemic response for SARS and COVID-19 will shine a light on the role of crisis experience on policy decision making. This research focuses on key theoretical contributions pertaining to the role of institutional science advice and scientific experts in crisis management. One core feature of pandemic crises that differs from other crises is that policy decisions are led by scientific evidence on the viral threat and up-to-date knowledge in public health. Politicians, policy-makers and economists, alone, do not have sufficient knowledge nor capability to reliably understand or make judgements or decisions on science-based policies. The findings reinforce the need for robust science advisory structures and knowledgeable scientific experts to solve health-related crises, tackling both the situational aspect of the crisis, as well as preventing the institutional aspect. This paper outlines the evolution of Hong Kong's science advisory structures and use of experts over time in response to two major pandemics, and how pandemic crisis management has resulted in temporary and/or permanent changes to Hong Kong's public health structures and policymaking.

Methodology. This research takes the form of a descriptive, in-depth case study that conducts comparative analysis of the two pandemics within one political context. The aim is to draw parallels and contrasts in the policy responses, scientific advisory mechanisms, communications and management between the two pandemics, as experienced in Hong Kong. Broad research questions include: How did Hong Kong's experience of the SARS crisis fundamentally affect public health structures in preparation for future pandemics? Were the measures and structures in place during SARS and post-SARS sufficient for handling COVID-19? How, and why, was pandemic response different between SARS and COVID-19? Despite expected opacity in governmental decision-making processes that occur behind-the-scenes, the inclusion of a wide range of publicly available archival documents is used to paint a clear and complete picture of Hong Kong's public health mechanisms, past and present. This single, historical case study provides an institutionally focused account of the differences and changes in policy response in Hong Kong between its two most prominent pandemics: SARS and COVID-19. It is based largely on an analysis of policy documents, government statistics, media accounts and academic literature. For SARS, brochures and documents self-published by various governmental departments were used to assess the purpose and functions of advisory structures (e.g., Center for Health Protection, 2005). Guidelines and checklists used to instruct operational stakeholders (e.g., policy decision makers, hospital managers, frontline health workers, and 'cleansing' operators) were used to appraise the resources and processes required to deliver intended outputs and outcomes (e.g., HKSAR Government, 2003a). A review of the lessons learned from the SARS epidemics based on academic literature that evaluated governmental response to SARS and made recommendations for future policy change was included (e.g., Lee, 2003; SARS Expert Committee, 2003a). For COVID-19, official archival documents were more centralised; due to the long-lasting nature of COVID-19 and a general increase in internet and digital media use, the relevant documents, notices, updates and guidance distributed by the government were accessible through a dedicated, one-stop "COVID-19 Thematic Website" launched and revamped in February 2020 (HKSAR Government, 2020h). This centralised website links to multiple other official departments' and press conference directories. Given the rise in digital, mobile and social media for COVID-19 information dissemination, much of governmental communication to the press and the public were channelled through press conferences over live stream platforms, as well as social media platforms. Using these sources, this research tracked, in real time, the government's policy responses and any changes or updates to scientific advisory mechanisms, such as the appointment of scientific experts on vaccinations.

- Hong Kong performed relatively well in 2020 without full lockdowns: by 12/31/2020 there were 8,846 confirmed cases and 148 deaths in a population of ~7.5 million (including ~1.37 million aged 65+) (Ritchie et al., 2022). - Post-SARS reforms established the Centre for Health Protection (CHP) with six branches and seven scientific committees, creating standing capacities for surveillance, infection control, laboratory services, emergency response, and risk communication, which were activated early in 2020. - In January 2020 the HKSAR Government rapidly launched the Preparedness and Response Plan and set up a Steering Committee and Command Centre with four workgroups (Disease Prevention and Control; Responses and Actions; Public Participation; Communications) and an informal expert advisory group of four eminent medical scientists. - Compared to 2003, response speed and coordination improved: the Plan was launched eight days after first official accounts (Dec 27, 2019 vs Jan 4, 2020), whereas during SARS key structures took weeks to months to form. - Science advice mechanisms differed between SARS and COVID-19 due to epidemiology: SARS’s severe symptoms concentrated decisions within HA and hospitals; COVID-19’s milder but more transmissible nature required broader policies (testing, tracing, vaccination, social measures, border controls) and wider expert input. - Guidance during COVID-19 was more frequent (e.g., six consensus recommendations in first 7 months by the Scientific Committee on Emerging and Zoonotic Diseases), though public communications occasionally sent mixed messages (e.g., early mask guidance reversal). - Political context mattered: trust in government hit a low (14% trust; 76% distrust, Feb 2020), affecting acceptance of measures; only 1.78 million (~24%) joined the 2020 Universal Community Testing Programme; vaccine hesitancy persisted despite advisory panels. - Technology deployment aided response (e-health monitoring, contact tracing apps, reusable masks), illustrating the growing role of innovation. - During the fifth wave in early 2022 (beyond the core 2020 focus), hospitals were overwhelmed and deaths per population peaked globally, prompting assistance from Mainland China and raising questions about policy direction and the credibility of advisory structures.

The study shows that Hong Kong’s institutional memory of SARS directly shaped swift early COVID-19 responses through established structures (CHP, scientific committees, emergency plans) and trusted experts. These mechanisms addressed the research questions by demonstrating how post-SARS reforms enabled more rapid and coordinated crisis management during COVID-19 and how differences in disease characteristics necessitated distinct advisory configurations and policy emphases. However, the political 'new normal' of low governmental trust constrained public compliance, moderating the effectiveness of even well-designed, science-led interventions. The comparison highlights that robust advisory systems and credible experts are necessary but not sufficient; crisis outcomes also depend on legitimacy, coherent communication, and adaptability. The evolution from hospital-centric, clinically focused SARS advisory processes to broader, cross-government structures for COVID-19 reflects institutional learning and adaptation. Yet, gaps remained in interdisciplinary breadth (e.g., economics, mental health, social welfare) and transparency, which limited public buy-in and hindered implementation of contentious measures like mass testing and vaccination. These findings underscore the significance of aligning scientific advice, political context, and public communication to translate expertise into accepted policy.

Hong Kong’s response to the COVID-19 pandemic had been directly shaped by its experience with SARS in 2003. In January 2020, as the scale of the pandemic emerged, the Hong Kong SAR Government was able to leverage on a series of existing policies, structures and advisory groups. The expert working groups established under the name of HA during SARS was the predecessor, while the CHP, established under DH on the basis of the reflection on SARS, laid the foundation of the scientific advisory system in place in 2020. Since the establishment of CHP, Hong Kong had eventually formed a scientific advisory mechanism led by government departments and involving experts from various organisations and fields to respond to public health incidents. From the SARS to the post-SARS period, and then during the COVID-19 period in 2020, the scientific advisory mechanism had become progressively more complex and flexible. Specifically, during the SARS and post-SARS periods, the scientific advisory mechanism mainly included officials from DH and HA as well as experts in the fields of medicine (especially respiratory and critical care medicine), pharmacology and public health. In the response to COVID-19, it had involved experts from broader and more fields, in order to adapt to the characteristics of this new epidemic. However, the range of expertise had not extended to areas such as economics, mental health social welfare, and retained a bias towards different areas of public health and medicine. Moreover, during COVID-19, the scientific advisory mechanism was no longer limited to CHP, DH and HA. The government had expanded its organisational structure to enhance interdisciplinary collaboration with other government departments under the framework of the Steering Committee. In addition to the use of these formalised advisory structures, the government had also relied extensively on well-respected local experts as a key part of its public communications strategy and receiving science advice. Three experts, in particular, had visibly communicated their science advice and expert opinions through various public-facing media channels, such as radio talk shows, televised programmes and press conferences, with much of Hong Kong’s population paying attention. With only medical experts in the government’s expert advisory panel, the panel’s specialty was somewhat confined to science advice, while there was a lack of diversity in terms of other potential experts who could advise more appropriately on, for example, the economy, schools and industry, all of which were greatly affected by the COVID-19 pandemic. Our full understanding of the roles of science advisory groups and experts in actual decision making still remains limited. The number of formal documents and statements issued by the advisory committees has been quite scant and transparency around the contents, or even schedules, of the meetings and interactions with key decision makers was low. Even the process through which experts were identified and appointed remains unclear. More research, such as interviews with specific science advisors, is required to develop a fuller, behind-the-scenes picture of how science advice was developed and communicated to decision makers, as well as the public. Furthermore, this research highlights the importance of understanding public trust in government, scientific experts and other key civic leaders, and this requires more extensive research in various political environments similar and dissimilar to Hong Kong in 2020, in order to better understand the strengths and weaknesses of the science advisory systems in place. A pandemic can indeed be defined theoretically as a crisis. Based on Rosenthal and Kouzmin (1997), the COVID-19 pandemic posed as an urgent threat to Hong Kong’s healthcare system, economy, livelihoods and its usual sense of safety and unity, and with each subsequent outbreak, policy-makers were required to make swift and vital decisions under high uncertainty and time pressure, but also immense public and political pressure. While expert science advice may help to avert a pandemic’s situational crisis, it may not necessarily prevent the onset of an institutional crisis, which could be fuelled by internal factors like politics and poor inter-agency communication, as well as external factors like low public trust in government and a highly polarised, defiant public. In practice, a pandemic can also be framed as an invaluable opportunity for policy learning and for strengthening crisis leadership. As Hong Kong enters the recovery phase of the crisis management cycle, it must reflect carefully on and learn from its successes as well as its mistakes and failures, lest it stays unprepared for the next potential wave or the next pandemic. Just as COVID-19 had learned lessons from SARS, will our next pandemic have learned lessons from COVID-19?

- Single-case, historical case study focused on Hong Kong limits generalizability beyond this political and institutional context. - Significant opacity in governmental decision-making processes and limited transparency around advisory committee meetings, documents, and expert appointment procedures constrain understanding of how advice influenced policy. - Few formal documents or public statements from advisory committees; reliance on publicly available archival materials and media may omit behind-the-scenes dynamics. - Public trust and political polarization affected acceptance of policies, complicating attribution of outcomes solely to advisory mechanisms.