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COVID-19 Update

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Since our last newsletter, the recent increase in cases has continued to settle in response to social distancing measures. There is no doubt about the effectiveness of social distancing in the management of COVID-19. The challenge is to balance our evolving understanding of the impact of the disease, on both individuals and the health system, with the social and economic costs of the public health interventions. This balance must be made within the specific context of the social, cultural and economic needs of the people of Hong Kong.

As we have previously described, the control of epidemics of infectious disease will ultimately always involve political decisions. Restriction of movement and quarantine are decisions which balance the rights of the individual against the rights of the majority. Population testing and tracking bring new practical and ethical challenges. As does the infodemic, which brings enormous amounts of information, misinformation and increasingly disinformation. Politicization of health interventions, from all sides of the political spectrum, risks harming population health by damaging trust in public health institutions. As we have consistently advised, Information and education are key factors in the management of infectious disease. Critically analyse all information, including ours, and ask if it is rational and logical.

This week the Hong Kong government has commenced mass testing. The challenges of mass testing programs have recently been described in an editorial in the British Medical Journal (BMJ).In order to understand the perceptions of this intervention within our population, we conducted a study of patient attitudes to mass testing in Hong Kong. We surveyed 3,044 patients who had previously volunteered for the seroprevalence study which we undertook in association with the University of Hong Kong. This cohort had already volunteered for testing for COVID-19, including blood sampling on 458 children. The survey was conducted over 48 hours including the day before and the first day of the testing program. We received 1,013 responses to our survey (response rate of 33 percent). Analysis of respondents indicated that 19% of patients intended to take part in the testing program and 81% indicated that they would not.

Unsurprisingly the OT&P population tended towards an international cohort. Of respondents, 84% have lived in Hong Kong for more than 6 years whilst 44% of patients were either born in Hong Kong or have lived here for more than 20 years. Younger patients were less likely to undertake testing. Patients aged 19-34 years (9%), aged 35-59 (19%) and >60 (25%). The most important reason given for not testing is a fear of compulsory hospitalisation or quarantine of close contacts (35%). This is particularly the case for families. Fear of separation from children was the most common comment in the free-text responses. For patients age 19-34 years, 54% describe quarantine as the greatest obstruction to testing. This data is supported by comments in our day to day practice. Moving towards home quarantine for close contacts and even asymptomatic positive cases has the potential to significantly increase community uptake in voluntary testing programs.

There is a genuine academic debate about the cost-effectiveness of testing an entire population rather than selective samples of higher risk cohorts. However, there is general agreement amongst medical experts that increased testing capacity is a good thing and the tests which are used in the Hong Kong program are valid and appropriate. The medical debate is really over population selection, the timing of testing and the maximal cost-benefit of testing interventions. The goals of the current mass testing program can be considered to be:

  1. To cut off transmission chains by identifying asymptomatic infections.
  2. To make an evidence-based assessment of community prevalence.
  3. To establish and test systems and processes for future testing programs.

Testing is likely to be a key component of management of COVID-19 for some time. Understanding the optimal strategies for testing, as with other public health interventions, is best achieved on the basis of evidence not emotion. The results of our survey and further analysis are available here.

In our last newsletter we explained the importance of the T-cell response in the immunity of COVID-19. We are involved in a research project with the University of Hong Kong looking at T-cell immunity. Evidence is evolving internationally that suggests that the T-cell response will be important in COVID-19, as it has shown to be for SARS and MERS. Ultimately, unless the SARS-COV-2 virus dies and disappears, the options of population resistance are limited to natural immunity or immunization. Strong T-cell reactions are generally positive in both situations.

There are a number of promising vaccine candidates which have published early results in international journals. As with much of the noise around COVID-19, it is important to maintain a sense of balance. As we stated in our Newsletter of 17th April it remains possible that small quantities of vaccine may be available for high-risk workers by late 2020. Realistically widespread vaccine supply is unlikely before mid to late 2021. This would still represent an extraordinary achievement. Current evidence of both B and T cell response to several vaccine candidates is very positive but it would be imprudent to widely disseminate a vaccine without more data on safety and efficacy.

The incidence of COVID-19 infection is still rising but mortality rates seem to be falling in many locations. It is not yet clear whether this change reflects different demographics, with increasing numbers of younger people being infected, whether newer mutations are less severe, whether masks and social distancing results in lower viral load resulting in less severe disease or whether population T-Cell immunity is impacting the evolution of the epidemic. Better treatment remains a further option and we have combinations of knowns and unknowns. As so often time and further evidence from locations with different strategies will be key.

The 2020-2021 Influenza vaccinations are now available in all our clinics. In the current context, we recommend vaccination for everybody over 6 months of age. The Influenza vaccination does not protect against COVID-19 but boosting individual and population immunity reduces the risks of any outbreak of infectious illness taking hold. Continuing the focus on prevention, a healthy lifestyle reduces the likelihood and severity of complications of infectious illness and particularly COVID-19. Now is a time to focus on health and well-being rather than disease. The gyms are opening and the cooler weather gives a great opportunity to boost Vitamin D levels by exercising outdoors.

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