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LCQ17: Strategy of "preventing the importation of cases" to cope with the epidemic
     Following is a question by the Hon Starry Lee and a written reply by the Secretary for Food and Health, Professor Sophia Chan, in the Legislative Council today (May 26):
     It has been reported that some experts have pointed out, as the coronavirus causing Coronavirus Disease 2019 (COVID-19) has been mutating incessantly, certain variants of COVID-19 virus (e.g. those variants first appearing in France and India) have higher transmissibility, can evade the testing methods commonly used, or reduce the efficacy of the vaccines. On the other hand, certain countries, in the light of the easing of their local epidemic situations, have one after another relaxed their immigration restrictions to a limited extent. With the people of various places making increasingly frequent cross-boundary travels in the latter half of this year, the strategy of "preventing the importation of cases" adopted in Hong Kong to cope with the epidemic may face greater challenges. In this connection, will the Government inform this Council:
(1) of the respective up-to-date numbers of (i) imported and (ii) local confirmed cases recorded in Hong Kong which involved variants of COVID-19 virus, with a breakdown by variant; the places/countries from which the imported cases mainly originated;
(2) whether it has assessed the risk of various variants of COVID-19 virus being imported into Hong Kong; if so, of the details; if not, the reasons for that;
(3) whether it will adjust the existing testing methods or adopt new testing methods to prevent variants of COVID-19 virus from evading testing successfully; if so, of the details; if not, the reasons for that;
(4) given that some variants of COVID-19 virus may reduce the efficacy of the vaccines, what other effective strategies the Government has in place, before acquiring vaccines of the next generation against such variants, to prevent the epidemic from deteriorating due to the importation of such variants; and
(5) whether it has assessed the pressure on the local manpower and facilities for virus testing to be brought about by the imminent plans to relax immigration restrictions to be implemented in various places; if so, of the details, and whether there are corresponding measures; if there are not corresponding measures, the reasons for that?
     For local confirmed cases of infection involving mutant strains, the Government has stayed vigilant and adopted stringent measures decisively and swiftly, with an aim to cutting the transmission chain in the community as quickly as possible. Although cases involving mutant strains have not yet caused an outbreak in the community, we should not let our guard down. It is essential for us to take all necessary measures to strengthen epidemic control by guarding against the importation of cases and the resurgence of domestic infections, and to further enhance the precision of the control measures to be taken in a bid to achieve the target of "zero infection" with the support and cooperation of the general public.
     My reply to the various parts of the question raised by Hon Starry Lee is as follows:
(1) Currently, the World Health Organization has included the following as variants of concern (VOC): the variant B.1.1.7 which was first detected in the United Kingdom; the variant B.1.351 which was first detected in South Africa; the variant P.1 which was first detected in Brazil; and the variant B.1.617 which was first detected in India. 

     Between December 2020 and May 20, 2021, over 260 cases carrying the N501Y mutant strain had been detected in Hong Kong, including 145 cases with B.1.1.7 mutant strain, 49 cases with B.1.351 mutant strain and one case with B.1.617 mutant strain. There are also 100 cases carrying L452R but not the N501Y mutant strain, including over 70 cases with the B.1.617 mutant strain.
     Among the above cases with N501Y mutant strain, there are 10 local cases which are involved in the same cluster.  The remaining cases are either imported or epidemiologically linked to imported cases.
     Among the imported cases carrying the N501Y mutant strain, most cases were from the Philippines (42.4 per cent), followed by Pakistan (20 per cent) and India (10.2 per cent).
     For the imported cases carrying L452 but not N501 mutant strain, the majority were from India (70.7 per cent).  Cases imported from Nepal made up 9.2 per cent of the cases.
(2) and (4) As the pandemic is still raging globally, Hong Kong cannot afford to drop its guard on entry prevention and control measures. To achieve the objective of preventing the importation of cases as far as practicable, the Government has implemented corresponding anti-epidemic measures based on prevention and control risk assessments.
     Currently, persons arriving at Hong Kong (including exempted persons), whether via the airport or land boundary control points, are required to undergo nucleic acid tests. For airport, after having their samples collected, regular arrivals must wait to ensure that their results are tested negative before they may proceed to designated quarantine hotels for compulsory quarantine (i.e. the "test and hold" arrangement), with a view to lowering the risk of spreading the virus to the community. Depending on what places the relevant persons have stayed in during the relevant period, these persons are subject to a number of tests during compulsory quarantine and may be subject to compulsory testing after quarantine.
     As the global epidemic situation remains severe with the new virus variants still ravaging many parts of the world, the Government needs to maintain the 21-day compulsory quarantine requirement for most persons who have stayed overseas, especially high-risk places. By adopting a risk-based approach the Government has implemented the respective boarding, quarantine and testing arrangements based on the risk levels of places where the arriving persons have stayed in. Places outside China are categorised into the extremely high-risk Group A1 specified places, the very high-risk Group A2 specified places, the high-risk Group B specified places, the medium-risk Group C specified places, and the low-risk Group D specified places. Except for Group D specified places, the basic quarantine requirement for those who have stayed in the remaining places is still 21-day compulsory quarantine in designated quarantine hotels. The basic quarantine requirement for persons who have only stayed in Group D specified places is 14-day compulsory quarantine in designated quarantine hotels.
     Meanwhile, persons arriving at Hong Kong, even if they were fully vaccinated, those who have stayed in Taiwan, Group B specified places or Group C specified places are still required to undergo 14-day compulsory quarantine in designated quarantine hotels, while fully vaccinated persons who have stayed in Group D specified places are still also required to undergo 7-day compulsory quarantine in designated quarantine hotels. Persons who have completed shortened compulsory quarantine are required to self-monitor for seven days and undergo compulsory testing.
     To address the risk of importation of mutant strains of the virus from very high-risk places, the Government implemented on April 14, 2021 and tightened on April 29 the place-specific flight suspension mechanism. Under the mechanism, if among all passenger flights from the same place, regardless of airline, a total of five or more passengers were confirmed positive by arrival tests for COVID-19 with the N501Y mutant strain or other relevant virus mutation which may potentially pose similar risks to Hong Kong's public health within a seven-day period, or a total of 10 or more passengers were confirmed positive by any tests (including tests conducted during quarantine) with the N501Y mutant strain or relevant virus mutation within a seven-day period, the Government will prohibit all passenger flights from that place from landing in Hong Kong, and will specify that relevant place as an extremely high-risk Group A1 specified place, so as to stop persons from the relevant place from travelling to Hong Kong via transit.
     As a measure to manage the flight resumption arrangements more cautiously under the mechanism, the Government will conduct risk assessments for comprehensive reviews of relevant factors such as the epidemic situation of the relevant places, vaccination rate, and the prevalence of new virus variants before determining whether it is appropriate to remove the flight suspension. Due to the need to review the epidemic situation of the place concerned, the flight suspension mechanism will not be lifted automatically. The Government will continue to closely monitor the developments of the epidemic situation both globally and locally, and will further adjust the boarding and compulsory quarantine requirements for persons arriving at Hong Kong from places with different risks when necessary.
     In order to prevent the spread of the virus in the community, the Centre for Health Protection (CHP) of the Department of Health (DH) has remained vigilant by strictly implementing contact tracing, testing and quarantine measures for confirmed case involving mutant strain detected in the community, and will continue to review relevant arrangements. Currently, the Government will screen and arrange genetic sequencing tests for preliminary positive samples detected in Hong Kong in order to closely monitor the situation of mutant strain. Furthermore, since the detection of the first confirmed case involving mutant strain in the community, the CHP has introduced more stringent measures.
     According to the latest arrangement, when a preliminary positive or positive case involving the N501Y mutant strain with unknown source has been identified, a restriction-cum-testing declaration would be made by the Government. Household contacts and people living in the same subdivided unit as the confirmed case will be subject to 21 days quarantine (instead of 14 days for confirmed cases without mutant strain). For close contacts of local confirmed cases detected with N501Y mutant strain who are able to document proof of completion of two doses of CoronaVac or Comirnaty COVID-19 vaccines, and that 14 days have passed from the date of receiving the second dose; results of PCR testing of the respiratory specimens taken on specified dates after admission to a quarantine centre being all negative; and positive IgG or total antibody against SARS-CoV-2 spike protein or positive surrogate neutralising antibody, the duration of quarantine can be shortened from 21 days to 14 days plus seven days of self-monitoring, counting from the last day of exposure to the confirmed case, and they are also subject to compulsory testing at a Community Testing Centre on Day 19. Besides, all residents living in the same building as the confirmed case would be subjected to compulsory testing on Days 3, 7, 12 and 19 counting from the day of announcement of the confirmed case. However, in case further cases are detected in the same building, all residents of the building would be classified as close contacts and placed under quarantine for 21 days as there would be evidence of transmission.
     Furthermore, vaccination is the current focus of the global anti-epidemic work, and is the most effective and thorough measure in the control of the epidemic. The two COVID-19 vaccines (i.e. the CoronaVac and Comirnaty vaccine) authorised for use in Hong Kong have been rigorously evaluated by the Advisory Panel that they are safe, efficacious and of good quality. According to the information from the World Health Organization, both vaccines can produce certain neutralising antibodies against the mutant strain involved in local confirmed cases.
     Drawing from international experience, even in the face of mutant strains, countries which have commenced large-scale vaccination programmes are able to improve their epidemic situation as the vaccination coverage rate increases. In fact, unless with contraindications, the vast majority of people are suitable for COVID-19 vaccination. To protect ourselves, our family and friends, and to build a herd immunity barrier for protection, we urge the public to get vaccinated without delay.
(3) The Public Health Laboratory Services Branch of the CHP conducts regular assessment to ensure that the COVID-19 RT-PCR testing platforms being used by the DH, the Hospital Authority and outsourced private laboratories are able to detect the variants.
(5) As mentioned above, persons arriving at Hong Kong (including exempted persons), whether via the airport or land boundary control points, are required to undergo nucleic acid tests upon arrival. There are corresponding testing requirements during the compulsory quarantine period and after completion of quarantine.
     The Government have been implementing virus testing in accordance with the principle of "early identification, early isolation and early treatment", and has been stepping up surveillance and testing efforts in a multi-pronged approach. The current maximum daily testing capacity of public and private laboratories has been substantially increased to approximately 100 000 tests per day (without sample pooling). The existing testing capacity is sufficient to meet the demand for virus testing in Hong Kong and the Government will continue to closely monitor the situation.
Ends/Wednesday, May 26, 2021
Issued at HKT 15:56
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