Special Session 4 - COVID-19: A Local Perspective

The Hong Kong SAR Government has implemented timely measures since early 2020 to enhance surveillance and prevention of COVID-19. Five waves of infection have occurred, with the first four waves happening in the pre-vaccination era and totaling around 12,500 cases. The first two waves in 2020 (from January to February and from March to April respectively) were mainly imported cases and small clusters of local transmission, while widespread community outbreaks occurred in the 3rd and 4th waves from July to September 2020 and from November 2020 to March 2021, respectively. Both were controlled through aggressive contact tracing, community testing, and stringent social distancing measures.


Hong Kong managed to maintain a dynamic zero-COVID state from April to December 2021. Most cases during this time were imported cases, with sporadic spillovers that did not result in sustained spread. Imported cases of Omicron variant have been detected since mid-November 2021, sparking the 5th wave in late December 2021.


The 5th wave has recorded around 2.86 million cases (as of January 29, 2023) with three periods of upsurge (February to March predominated by BA.2; August to September predominated by BA.5; and November to December predominated by BA.5). Airborne transmission of Omicron was demonstrated in outbreaks in restaurants and designated quarantine hotels, making containment difficult through contact tracing and social distancing measures. Large outbreaks have occurred in residential care institutions (RCH) with a median attack rate of around 85%. Vertical transmissions in high-rise residential buildings were also common.


The case fatality rate (CFR) among the elderly was much higher than in younger age groups, with elderly aged 60 years or older constituting 25% of cases but 95% of deaths. Among the 13115 fatal cases recorded in 5th wave, 93% had chronic diseases and 47% were RCH residents. The overall CFR decreased from 1.68% during the 1st to 4th waves to 0.45% in the 5th wave. Cases in the 5th wave who had received at least 3 doses of vaccination had a CFR of 0.16% as compared to 0.80% among cases with 2 doses or less. The vaccination coverage has been boosted up through various measures and extensive interdepartmental and multisectoral efforts. With gradual increase in vaccination coverage, hybrid immunity, and the more extensive use of oral antiviral treatment in community settings, the CFR in the 5th wave dropped from 0.78% (2.85% among unvaccinated) between January and May 2022 to 0.23% (0.67% among unvaccinated) between June 2022 and January 2023.


The Centre for Health Protection will continue to closely monitor the evolving COVID-19 situation through established surveillance systems, including genetic characterization and sewage surveillance.

During the COVID-19 pandemic, stringent border control measures have been implemented to prevent importation of the disease into Hong Kong. In the early stage, strengthened temperature screening and health declaration requirement were implemented. To reduce cross-boundary movement of travellers, passenger clearance service for all boundary control points (BCPs) were suspended except the control points at Hong Kong International Airport, Shenzhen Bay and the Hong Kong-Zhuhai-Macao Bridge since early February 2020.  


Subsequently, various subsidiary legislations of the Prevention and Control of Disease Ordinance have been enacted to provide legal basis for the implementation of additional inbound control measures.  Compulsory quarantine requirement was imposed for Mainland returnees since early February and had later extended to all inbound travellers. As the disease gradually spread all over the world, pre-departure testing and vaccination requirement for travellers arriving by flights as well as flight suspension mechanism were introduced. 


Since early April 2020, all inbound travellers arriving by flights were required to self-collect a deep throat saliva specimen at the Temporary Specimen Collection Centre for SARS-CoV-2 PCR.  It was changed to collection of combined nasal and throat swab by dedicated staff in mid-December 2020.  From 15 December 2020 to 28 December 2022, swab specimens were collected from about 2.43 million travellers with over 44,400 positive detection which corresponded to a positive rate of 1.89%. 


Apart from inbound control measures, Hong Kong has also implemented SARS-CoV-2 PCR testing for outbound travellers to the Mainland at the BCPs in March 2022 so as to prevent the exportation of local cases and to support the Mainland’s anti-epidemic efforts. About 565,700 travellers were tested and over 8,730 positive cases (Positive rate: 1.54%) were identified.

The Government Covid-19 Vaccination Programme has been instrumental in curbing the spread of the virus and protecting public health. The programme has faced numerous operational challenges, including planning and allocation of manpower resources, managing vaccine hesitancy among priority groups, and ensuring cold chain requirements for ultra-cold vaccine storage. 


Despite these challenges, the programme has successfully administered over 20 million doses of COVID-19 vaccines over the past two years, achieving a 94% completion rate for the primary series and over 84% for booster doses.


This presentation will delve into the challenges encountered by the programme and the actions taken to overcome them. The planning and allocation of manpower resources, including the deployment of healthcare workers and the training of volunteers, has been a major challenge.


Furthermore, the presentation will discuss the cold chain requirements for ultra-cold vaccine storage and inventory management. The programme has implemented a robust cold chain system to ensure the quality and safety of the vaccines, and the presentation will explore the challenges encountered and the solutions employed.


The presentation will highlight the planning process and the role of big data and IT in supporting policy makers to strategize the programme's reach to priority groups. Strategies employed to combat vaccine hesitancy, such as targeted communication campaigns and community outreach programmes will also be discussed.