Effectiveness of mRNA and inactivated COVID-19 vaccines: A test-negative study in an infection-naïve Hong Kong population.

OBJECTIVE: Assess real-world effectiveness of vaccines against COVID-19. METHODS: A test-negative study was conducted in January-May 2022 during an Omicron BA.2 wave in Hong Kong. COVID-19 was identified by RT-PCR. 1-1 case-control matching was based on propensity score with vaccine effectiveness adjusted for confounders. RESULTS: Altogether, 1781 cases and 1737 controls aged 3-105 years were analysed. The mean lag time from the last dose of vaccination to testing for SARS-CoV-2 was 133.9 (SD: 84.4) days. Two doses of either vaccine within 180 days offered a low effectiveness against COVID-19 of all severity combined (VEadj [95% CI] for BNT162b2: 27.0% [4.2-44.5], CoronaVac: 22.9% [1.3-39.7]), and further decreased after 180 days. Two doses of CoronaVac were poorly protective 39.5% [4.9-62.5] against severe diseases for age ≥ 60 years, but the effectiveness increased substantially after the third dose (79.1% [25.7-96.7]). Two doses of BNT162b2 protected age ≥ 60 years against severe diseases (79.3% [47.2, 93.9]); however, the uptake was not high enough to assess three doses. CONCLUSIONS: The current real-world analysis indicates a high vaccine effectiveness of three doses of inactivated virus (CoronaVac) vaccines against Omicron variant, whereas the effectiveness of two doses is suboptimal.

Effects of Gut Microbiome Modulation on Reducing Adverse Health Outcomes among Elderly and Diabetes Patients during the COVID-19 Pandemic: A Randomised, Double-Blind, Placebo-Controlled Trial (IMPACT Study).

Gut microbiota is believed to be a major determinant of health outcomes. We hypothesised that a novel oral microbiome formula (SIM01) can reduce the risk of adverse health outcomes in at-risk subjects during the coronavirus disease 2019 (COVID-19) pandemic. In this single-centre, double-blind, randomised, placebo-controlled trial, we recruited subjects aged ≥65 years or with type two diabetes mellitus. Eligible subjects were randomised in a 1:1 ratio to receive three months of SIM01 or placebo (vitamin C) within one week of the first COVID-19 vaccine dose. Both the researchers and participants were blinded to the groups allocated. The rate of adverse health outcomes was significantly lower in the SIM01 group than the placebo at one month (6 [2.9%] vs. 25 [12.6], p < 0.001) and three months (0 vs. 5 [3.1%], p = 0.025). At three months, more subjects who received SIM01 than the placebo reported better sleep quality (53 [41.4%] vs. 22 [19.3%], p < 0.001), improved skin condition (18 [14.1%] vs. 8 [7.0%], p = 0.043), and better mood (27 [21.2%] vs. 13 [11.4%], p = 0.043). Subjects who received SIM01 showed a significant increase in beneficial Bifidobacteria and butyrate-producing bacteria in faecal samples and strengthened the microbial ecology network. SIM01 reduced adverse health outcomes and restored gut dysbiosis in elderly and diabetes patients during the COVID-19 pandemic.

Factors Associated with Vaccination Uptake among Young Children: A Follow-Up Study of 1799 Toddlers.

Childhood vaccination is crucial to protect young children from harmful infectious diseases. This study aimed to investigate the recent childhood immunization rate of recommended and additional vaccinations and identify the factors affecting the vaccination uptake of young children in Hong Kong. The self-administrated questionnaires were distributed to parents of toddlers aged 2 to 5. They were asked to provide information on (1) socioeconomic demographic factors; (2) experiences during pregnancy; and (3) the medical history of the toddler. A total of 1799 responses were collected. Children were more likely to be fully vaccinated when they were at a younger age (aOR = 0.61, 95% CI: 0.48-0.78, p < 0.001), the first child in the family (aOR second-born = 0.62, 95% CI: 0.48-0.81, p < 0.001; aOR third-born = 0.33, 95% CI: 0.19-0.55, p < 0.001), had a higher household income (aOR HKD 15,000-HKD 29,999 = 1.80, 95% CI: 1.27-2.55, p = 0.001; aOR ≥ HKD 30,000 = 3.42, 95% CI: 2.39-4.90, p < 0.001; compared with

Factors associated with weight gain during COVID-19 pandemic: A global study.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has resulted in changes in lifestyle habits and experiences of mental health outcomes, some of which were possibly related to weight gain, leading to an increase in the prevalence of obesity, which is associated with the development of several severe diseases. Concerns regarding weight gain and its impact on health outcomes are prevalent worldwide, with obesity being one of the highest causes of mortality in current society. METHODS: A self-reported questionnaire collected data from participants aged 18 years of age and above from 26 countries and regions worldwide. Post-hoc multiple logistic regression analyses have been done to evaluate the association between demographic and socioeconomic factors, and the perspectives that were identified to be associated with weight gain. RESULTS: Participants belonging to a younger age group; with a higher level of education; living in an urban area; living with family members; employed full-time; and had obesity were found to be more vulnerable to weight gain. After adjusting for socio-demographic factors, participants who were quarantined; exercised less prior to the pandemic; consumed unhealthy foods; and reported negative thoughts such as helplessness and the perceived risk of COVID-19, were more likely to experience weight gain; while negative thoughts such as having no means of control over the COVID-19 pandemic and the consequences of the COVID-19 pandemic will have great personal effect were associated with females, students, and people living in the rural area. CONCLUSIONS: Weight gain risk during the pandemic was significantly associated with certain socio-demographic and COVID-19 related factors. To improve public health outcomes, future research should conduct a longitudinal evaluation on the effects of COVID-19 experiences upon health choices. Streamlined mental support should also be provided to the vulnerable groups which were prone to negative thoughts that were associated with weight gain.

Understanding the Prevalence and Associated Factors of Behavioral Intention of COVID-19 Vaccination Under Specific Scenarios Combining Effectiveness, Safety, and Cost in the Hong Kong Chinese General Population.

BACKGROUND: The prevalence of coronavirus disease 2019 (COVID-19) vaccination is very critical in controlling COVID-19. This study mainly aimed to (1) investigate behavioral intentions of COVID-19 vaccination under various specific scenarios, and (2) associated factors of the afore-mentioned vaccination intentions. METHODS: A random anonymous telephone survey interviewed 450 Chinese adults from September 16-30, 2020 in Hong Kong, China. Nine scenarios of behavioral intentions of COVID-19 vaccinations were measured combining effectiveness (80% versus 50%), safety (rare versus common mild side effect), and cost (free versus HK$ 500). RESULTS: The prevalence of behavioral intentions of COVID-19 vaccination under the 9 specific scenarios was very low and varied greatly (4.2% to 38.0%). The prospective countries of manufacture also influenced vaccination intention (eg, Japan: 55.8% vs China: 31.1%). Only 13.1% intended to take up COVID-19 vaccination at the soonest upon its availability. The attributes of effectiveness and side effect influenced vaccination intention most. Positively associated factors of behavioral intentions of COVID-19 vaccination included trust/satisfaction toward the government, exposure to positive social media information about COVID-19 vaccines, descriptive norms, perceived impact on the pandemic, perceived duration of protectiveness, and life satisfaction. CONCLUSION: Intention of COVID-19 vaccination was low in the Hong Kong general population, especially among younger people, females, and single people. Health promotion is warranted to enhance the intention. The significant factors identified in this study may be considered when designing such health promotion. Future research is required to confirm the findings in other countries. Such studies should pay attention to the specific context of cost, safety, and effectiveness, which would lead to different responses in the level of behavioral intention of COVID-19 vaccination (BICV).

Cross-Clade Memory Immunity in Adults Following SARS-CoV-1 Infection in 2003.

Importance: Knowledge of the longevity and breath of immune response to coronavirus infection is crucial for the development of next-generation vaccines to control the COVID-19 pandemic. Objectives: To determine the profile of SARS-CoV-2 antibodies among persons infected with the closely related virus, SARS-CoV-1, in 2003 (SARS03 survivors) and to characterize their antibody response soon after the first and second doses of COVID-19 vaccines. Design, Setting, and Participants: This prospective cohort study examined SARS-CoV-2 antibodies among SARS03 survivors compared with sex- and age-matched infection-naive controls. Participants received the COVID-19 vaccines between March 1 and September 30, 2021. Interventions: One of the 2 COVID-19 vaccines (inactivated [CoronaVac] or messenger RNA [BNT162b2]) available in Hong Kong. Two doses were given according to the recommended schedule. The vaccine type administered was known to both participants and observers. Main Outcomes and Measures: SARS-CoV-2 antibodies were measured prevaccination, 7 days after the first dose, and 14 days after the second dose. Results: Eighteen SARS03 adult survivors (15 women and 3 men; median age, 46.5 [IQR, 40.0-54.3] years) underwent prevaccination serologic examination. The vast majority retained a detectable level of antibodies that cross-reacted with SARS-CoV-2 (16 of 18 [88.9%] with nucleocapsid protein antibodies and 17 of 18 [94.4%] with receptor-binding domain of spike protein antibodies); a substantial proportion (11 of 18 [61.1%]) had detectable cross-neutralizing antibodies. Twelve SARS03 adult survivors (10 women and 2 men) underwent postvaccination serologic examination. At 7 days after the first dose of vaccine, SARS03 survivors mounted significantly higher levels of neutralizing antibodies compared with controls (median inhibition: 89.5% [IQR, 77.1%-93.7%] vs 13.9% [IQR, 11.8%-16.1%] for BNT162b2; 64.9% [IQR, 60.8%-69.5%] vs 13.4% [IQR, 9.5%-16.8%] for CoronaVac; P < .001 for both). At 14 days after the second dose, SARS03 survivors generated a broader antibody response with significantly higher levels of neutralizing antibodies against variants of concern compared with controls (eg, median inhibition against Omicron variant, 52.1% [IQR, 35.8%-66.0%] vs 14.7% [IQR, 2.5%-20.7%]; P < .001). Conclusions and Relevance: The findings of this prospective cohort study suggest that infection with SARS-CoV-1 was associated with detectable levels of antibodies that cross-react and cross-neutralize SARS-CoV-2, which belongs to a distinct clade under the same subgenus Sarbecovirus. These findings support the development of broadly protective vaccines to cover sarbecoviruses that caused 2 devastating zoonotic outbreaks in humans over the last 2 decades.

Resilience level and its association with maladaptive coping behaviours in the COVID-19 pandemic: a global survey of the general populations.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has induced a significant global concern on mental health. However few studies have measured the ability of individuals to "withstand setbacks, adapt positively, and bounce back from adversity" on a global scale. We aimed to examine the level of resilience, its determinants, and its association with maladaptive coping behaviours during the pandemic. METHODS: The Association of Pacific Rim Universities (APRU) conducted a global survey involving 26 countries by online, self-administered questionnaire (October 2020-December 2021). It was piloted-tested and validated by an expert panel of epidemiologists and primary care professionals. We collected data on socio-demographics, socioeconomic status, clinical information, lifestyle habits, and resilience levels measured by the Brief Resilience Scale (BRS) among adults aged ≥ 18 years. We examined factors associated with low resilience level, and evaluated whether low resilience was correlated with engagement of maladaptive coping behaviours. RESULTS: From 1,762 surveys, the prevalence of low resilience level (BRS score 1.00-2.99) was 36.4% (America/Europe) and 24.1% (Asia Pacific). Young age (18-29 years; adjusted odds ratio [aOR] = 0.31-0.58 in older age groups), female gender (aOR = 1.72, 95% C.I. = 1.34-2.20), poorer financial situation in the past 6 months (aOR = 2.32, 95% C.I. = 1.62-3.34), the presence of one (aOR = 1.56, 95% C.I. = 1.19-2.04) and more than two (aOR = 2.32, 95% C.I. = 1.59-3.39) medical conditions were associated with low resilience level. Individuals with low resilience were significantly more likely to consume substantially more alcohol than usual (aOR = 3.84, 95% C.I. = 1.62-9.08), take considerably more drugs (aOR = 12.1, 95% C.I. = 2.72-54.3), buy supplements believed to be good for treating COVID-19 (aOR = 3.34, 95% C.I. = 1.56-7.16), exercise less than before the pandemic (aOR = 1.76, 95% C.I. = 1.09-2.85), consume more unhealthy food than before the pandemic (aOR = 2.84, 95% C.I. = 1.72-4.67), self-isolate to stay away from others to avoid infection (aOR = 1.83, 95% C.I. = 1.09-3.08), have an excessive urge to disinfect hands for avoidance of disease (aOR = 3.08, 95% C.I. = 1.90-4.99) and transmission (aOR = 2.54, 95% C.I. = 1.57-4.10). CONCLUSIONS: We found an association between low resilience and maladaptive coping behaviours in the COVID-19 pandemic. The risk factors identified for low resilience in this study were also conditions known to be related to globalization-related economic and social inequalities. Our findings could inform design of population-based, resilience-enhancing intervention programmes.

Results from the Hong Kong's 2022 report card on physical activity for children and adolescents

Background/objective This paper aimed to summarize the findings of the third (2022) Active Healthy Kids Hong Kong Report Card on Physical Activity for Children and Adolescents and evaluate the secular trends of physical activity related indicators. Methods Five behavioral indicators (Overall Physical Activity, Organized Sport and Physical Activity, Active Play, Active Transportation, and Sedentary Behavior), three outcome indicators (Physical Fitness, Sleep, and Obesity) and four sources of influence indicators (Family and Peers, School, Community and Environment, and Government) were assigned a letter grade (ranging from A+ to F or incomplete) based on the best available evidence following a harmonized approach developed by the Active Healthy Kids Global Alliance. Data sources included published journal articles, government reports, manual searches, and personal contacts;and consisted of both pre-COVID-19 and after-COVID-19 evidence. Results Grades for Overall Physical Activity (D−**) and Sedentary Behavior (D) deteriorated compared to the 2018 Report Card. The other three behavioral indicators, Organized Sport and Physical Activity, Active Play, and Active Transportation, were assigned B−, D, and B+, respectively. Physical Fitness (D), Sleep (C−), and Obesity (D−) obtained the same grades as in the 2018 Report Card. School (B) and Government (C+) grades slightly improved, while Community and Environment grade (B) was stable. Family and Peers was not graded due to insufficient evidence. Conclusions Despite slight improvements in influence indicators, physical activity and sedentary behavior have changed unfavorably for children and adolescents in Hong Kong. Strategic investments are needed to improve adoption and implementation of effective interventions.

Factors Associated with Vaccination Intention against the COVID-19 Pandemic: A Global Population-Based Study.

Several vaccines have been developed for COVID-19 since the pandemic began. This study aimed to evaluate the factors associated with COVID-19 vaccination intention. A global survey was conducted across 26 countries from October, 2020 to December, 2021 using an online self-administered questionnaire. Demographic information, socio-economic status, and clinical information were collected. A logistic regression examined the associations between vaccine intention and factors such as perceptions and the presence of chronic physical and mental conditions. The sample included 2459 participants, with 384 participants (15.7%) expressing lower COVID-19 vaccination intent. Individuals who identified as female; belonged to an older age group; had a higher level of education; were students; had full health insurance coverage; or had a previous history of influenza vaccination were more willing to receive vaccination. Conversely, those who were working part-time, were self-employed, or were receiving social welfare were less likely to report an intention to get vaccinated. Participants with mental or physical health conditions were more unwilling to receive vaccination, especially those with sickle cell disease, cancer history within the past five years, or mental illness. Stronger vaccination intent was associated with recommendations from the government or family doctors. The presence of chronic conditions was associated with lower vaccine intention. Individuals with health conditions are especially vulnerable to health complications and may experience an increased severity of COVID-19 symptoms. Future research should evaluate the effectiveness of interventions targeting the vaccine perceptions and behaviours of at-risk groups. As such, public awareness campaigns conducted by the government and proactive endorsement from health physicians may help improve COVID-19 vaccination intention.

Enabling Factors, Barriers, and Perceptions of Pneumococcal Vaccination Strategy Implementation: A Qualitative Study.

Invasive pneumococcal disease (IPD) is a leading cause of disability and mortality worldwide, particularly in the elderly population. With the implementation of the Government Vaccination Programme (GVP) and the Vaccination Subsidy Scheme (VSS), enabling factors and barriers in service provider scheme participation and vaccination uptake were examined in 32 interviews with doctors and 16 interviews with vaccine recipients. Interview data were analysed in NVivo 11.0 with reference to the Consolidated Framework for Implementation Research (CFIR) and the REAIM Framework to develop codes and themes. Barriers to pneumococcal vaccination uptake included concerns on vaccine efficacy and poor understanding of the disease and vaccine schemes, whilst service provider participation was hindered by ill-defined parameters for patient eligibility and time, location, and logistical constraints. Enabling factors to improve intervention implementation were involvement of the government and physicians to encourage participation, clarifying eligibility criteria, and improving individual knowledge of IPD and vaccination schemes. As participation rates in the GVP and VSS remains low in Hong Kong, efforts concentrating on health promotion strategies encouraging pneumococcal vaccination amongst the elderly population are recommended.

Seroprevalence of Unidentified SARS-CoV-2 Infection in Hong Kong During 3 Pandemic Waves.

Importance: Seroprevalence studies inform the extent of infection and assist evaluation of mitigation strategies for the COVID-19 pandemic. Objective: To estimate the prevalence of unidentified SARS-CoV-2 infection in the general population of Hong Kong. Design, Setting, and Participants: A prospective cross-sectional study was conducted in Hong Kong after each major wave of the COVID-19 pandemic (April 21 to July 7, 2020; September 29 to November 23, 2020; and January 15 to April 18, 2021). Adults (age ≥18 years) who had not been diagnosed with COVID-19 were recruited during each period, and their sociodemographic information, symptoms, travel, contact, quarantine, and COVID-19 testing history were collected. Main Outcomes and Measures: The main outcome was prevalence of SARS-CoV-2 infection. SARS-CoV-2 IgG antibodies were detected by an enzyme-linked immunosorbent assay based on spike (S1/S2) protein, followed by confirmation with a commercial electrochemiluminescence immunoassay based on the receptor binding domain of spike protein. Results: The study enrolled 4198 participants (2539 [60%] female; median age, 50 years [IQR, 25 years]), including 903 (22%), 1046 (25%), and 2249 (53%) during April 21 to July 7, 2020; during September 29 to November 23, 2020; and during January 15 to April 18, 2021, respectively. The numbers of participants aged 18 to 39 years, 40 to 59 years, and 60 years or older were 1328 (32%), 1645 (39%), and 1225 (29%), respectively. Among the participants, 2444 (58%) stayed in Hong Kong since November 2019 and 2094 (50%) had negative SARS-CoV-2 RNA test results. Only 170 (4%) reported ever having contact with individuals with confirmed cases, and 5% had been isolated or quarantined. Most (2803 [67%]) did not recall any illnesses, whereas 737 (18%), 212 (5%), and 385 (9%) had experienced respiratory symptoms, gastrointestinal symptoms, or both, respectively, before testing. Six participants were confirmed to be positive for anti-SARS-CoV-2 IgG; the adjusted prevalence of unidentified infection was 0.15% (95% CI, 0.06%-0.32%). Extrapolating these findings to the whole population, there were fewer than 1.9 unidentified infections for every recorded confirmed case. The overall prevalence of SARS-CoV-2 infection in Hong Kong before the roll out of vaccination was less than 0.45%. Conclusions and Relevance: In this cross-sectional study of participants from the general public in Hong Kong, the prevalence of unidentified SARS-CoV-2 infection was low after 3 major waves of the pandemic, suggesting the success of the pandemic mitigation by stringent isolation and quarantine policies even without complete city lockdown. More than 99.5% of the general population of Hong Kong remain naive to SARS-CoV-2, highlighting the urgent need to achieve high vaccine coverage.

COVID-19 Vaccine Hesitancy in a City with Free Choice and Sufficient Doses.

BACKGROUND: Vaccine hesitancy represents one of the major global health issues around the world. We examined the perception, attitude, perceived barriers and facilitation measures of receiving the COVID-19 vaccine in a Chinese population with free vaccine choices (Sinovac [Coronavac] vs. BioNTech/Fosun [Comirnaty]) and adequate doses. METHOD: We conducted a random telephone survey of the general population in 1195 subjects aged 18 years or above from 23 April 2021 to 8 May 2021 after two months of vaccine rollout. A descriptive analysis of the levels of enabling factors, obstacles and perception of COVID-19 vaccination was conducted using ANOVA and Chi-square tests for trend. RESULTS: Only 10.1% and 13.5% had received one and two COVID-19 vaccine doses, respectively. Among those who had not received any COVID-19 vaccine (75.4%), only 25.1% expressed their intention to receive in the coming 6 months. The barriers with the highest scores included "having heard of cases with serious adverse events or death after vaccination" (score: 8.17 out 10, 95% C.I. 7.99, 8.35), "lack of confidence on governmental recommendations" (7.69, 95% C.I. 7.47, 7.91), and "waiting for a better vaccine" (7.29, 95% C.I. 7.07, 7.52). The highest score for the impact of various incentives for vaccination was for "vaccine passports for overseas travel" (4.44, 95% C.I. 4.18, 4.71). CONCLUSIONS: Vaccine hesitancy is commonly observed in this Chinese population despite adequate provision of vaccine doses and choices. No single incentive is strong enough to promote vaccination, and multiple facilitation measures for different groups of population are needed to encourage vaccine uptake. Active clarification and promotion by medical professionals together with a variety of incentives are needed to drive vaccine uptake.

A global analysis of replacement of genetic variants of SARS-CoV-2 in association with containment capacity and changes in disease severity.

OBJECTIVES: To examine severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant replacement in association with containment capacity and changes in case fatality at country level. METHODS: Altogether, 69 571 full SARS-CoV-2 genomes collected globally within the first 6 months of the pandemic were examined. The correlation between variant replacement and containment capacity was examined by logistic regression models using the WHO International Health Regulation (IHR) score, the Oxford COVID-19 Government Response Tracker (OxCGRT) and the vulnerability index INFORM as proxies, while correlation with changes in monthly crude case fatality ratios was examined by a mixed effect model. RESULTS: At the global level, variant lineage G∗, characterized by the S-D614G mutation, replaced the older lineages L and S in March 2020. European countries-including Finland, France and Italy-were the first to reach a 50% increment of G∗, whereas only Singapore and South Korea had non-G∗ persisting throughout the first 6 months. Countries with higher IHR scores (ß-coefficient -0.001, 95%CI -0.016, -0.001; p 0.034) and higher stringency indexes (OxCGRT) (ß-coefficient -0.011, 95%CI -0.020, -0.001; p 0.035) were associated with lower levels of G∗ replacement, whereas higher vulnerability indexes (INFORM) (ß-coefficient 0.049, 95%CI 0.001, 0.097; p 0.044) were associated with higher replacement levels. Crude case fatality ratio showed a positive correlation with G∗ replacement (ß-coefficient: 0.034, 95%CI 0.011, 0.058; p 0.004), even after adjusting for testing capacity and other country-specific characteristics. CONCLUSIONS: SARS-CoV-2 variant lineage G∗ (S-D614G) replaced older lineages more efficiently in countries with lower containment capacity, and its possible association with increased disease severity deserves further investigation.

Acceptance of the COVID-19 vaccine based on the health belief model: A population-based survey in Hong Kong.

BACKGROUND: Vaccines for COVID-19 are anticipated to be available by 2021. Vaccine uptake rate is a crucial determinant for herd immunity. We examined factors associated with acceptance of vaccine based on (1). constructs of the Health Belief Model (HBM), (2). trust in the healthcare system, new vaccine platforms and manufacturers, and (3). self-reported health outcomes. METHODS: A population-based, random telephone survey was performed during the peak of the third wave of COVID-19 outbreak (27/07/2020 to 27/08/2020) in Hong Kong. All adults aged ≥ 18 years were eligible. The survey included sociodemographic details; self-report health conditions; trust scales; and self-reported health outcomes. Multivariable regression analyses were applied to examine independent associations. The primary outcome is the acceptance of the COVID-19 vaccine. RESULTS: We conducted 1200 successful telephone interviews (response rate 55%). The overall vaccine acceptance rate after adjustment for population distribution was 37.2% (95% C.I. 34.5-39.9%). The projected acceptance rates exhibited a "J-shaped" pattern with age, with higher rates among young adults (18-24 years), then increased linearly with age. Multivariable regression analyses revealed that perceived severity, perceived benefits of the vaccine, cues to action, self-reported health outcomes, and trust in healthcare system or vaccine manufacturers were positive correlates of acceptance; whilst perceived access barriers and harm were negative correlates. Remarkably, perceived susceptibility to infection carried no significant association, whereas recommendation from Government (aOR = 10.2, 95% C.I. 6.54 to 15.9, p < 0.001) was as the strongest driving factor for acceptance. Other key obstacles of acceptance included lack of confidence on newer vaccine platforms (43.4%) and manufacturers without track record (52.2%), which are of particular relevance to the current context. CONCLUSIONS: Governmental recommendation is an important driver, whereas perceived susceptibility is not associated with acceptance of COVID-19 vaccine. These HBM constructs and independent predictors inform evidence-based formulation and implementation of vaccination strategies.

Prospective Study Comparing Deep Throat Saliva With Other Respiratory Tract Specimens in the Diagnosis of Novel Coronavirus Disease 2019.

BACKGROUND: Self-collected specimens have been advocated to avoid infectious exposure to healthcare workers. Self-induced sputum in those with a productive cough and saliva in those without a productive cough have been proposed, but sensitivity remains uncertain. METHODS: We performed a prospective study in 2 regional hospitals in Hong Kong. RESULTS: We prospectively examined 563 serial samples collected during the virus shedding periods of 50 patients: 150 deep throat saliva (DTS), 309 pooled-nasopharyngeal (NP) and throat swabs, and 104 sputum. Deep throat saliva had the lowest overall reverse-transcriptase polymerase chain reaction (RT-PCR)-positive rate (68.7% vs 89.4% [sputum] and 80.9% [pooled NP and throat swabs]) and the lowest viral ribonucleic acid (RNA) concentration (mean log copy/mL 3.54 vs 5.03 [sputum] and 4.63 [pooled NP and throat swabs]). Analyses with respect to time from symptom onset and severity also revealed similar results. Virus yields of DTS correlated with that of sputum (Pearson correlation index 0.76; 95% confidence interval, 0.62-0.86). We estimated that the overall false-negative rate of DTS could be as high as 31.3% and increased 2.7 times among patients without sputum. CONCLUSIONS: Deep throat saliva produced the lowest viral RNA concentration and RT-PCR-positive rate compared with conventional respiratory specimens in all phases of illness. Self-collected sputum should be the choice for patients with sputum.

Stringent containment measures without complete city lockdown to achieve low incidence and mortality across two waves of COVID-19 in Hong Kong.

INTRODUCTION: An international city, Hong Kong, in proximity to the first epicentre of COVID- 19, experienced two epidemic waves with different importation pressure. We compared the epidemiological features of patients with COVID-19 in the context of containment policies between the first and second waves. METHODS: We retrieved information on the first 1038 cases detected in Hong Kong (23 January to 25 April 2020) to analyse the epidemiological characteristics including age/gender-specific incidence, clustering, reproduction number (Rt ) and containment delay; in relation to the containment measures implemented. Factors associated with containment delay were evaluated by multiple linear regression analysis with age, gender, epidemic wave and infection source as covariates. A time series of 5-day moving average was plotted to examine the changes across the two epidemic waves. RESULTS: The incidence and mortality (135.5 and 0.5 per 1 000 000 population) was among the lowest in the world. Aggressive escalation of border control correlated with reductions in Rt from 1.35 to 0.57 and 0.92 to 0.18, and aversions of 450 and 1650 local infections during the first and second waves, respectively. Implementing COVID-19 tests for overseas returners correlated with an upsurge of asymptomatic case detection, and shortened containment delay in the second wave. Medium-sized cluster events in the first wave were family gatherings, whereas those in the second wave were leisure activities among youngsters. Containment delay was associated with older age (adjusted OR (AOR)=1.01, 95% CI 1.00 to 1.02, p=0.040), male gender (AOR=1.41, 95% CI 1.02 to 1.96, p=0.039) and local cases (AOR=11.18, 95% CI 7.43 to 16.83, p<0.001), and with significant improvement in the second wave compared with the first wave (average: 6.8 vs 3.7 days). A higher incidence rate was observed for males, raising possibility of gender predilection in susceptibility of developing symptoms. CONCLUSION: Prompt and stringent all-round containment strategies represent successful measures in pandemic control. These findings could inform formulation and implementation of pandemic mitigation strategies.

Relationships between Physical and Social Behavioural Changes and the Mental Status of Homebound Residents in Hong Kong during the COVID-19 Pandemic

In Hong Kong, social distancing has been adopted in order to minimise the spread of COVID-19. This study aims to examine the changes in physical health, mental health, and social well-being experienced by local residents who were homebound during the pandemic. An online questionnaire in both Chinese and English versions was completed by 590 eligible participants from 24 April to 13 May 2020. The questionnaire found that individuals aged 18 to 25 years spent more time resting and relaxing but experienced more physical strain. Working status was associated with social contact, with participants working full-time jobs scoring higher in "maintaining social communication via electronic means"and "avoiding social activities outside the home". Additionally, approximately one third of the participants (29.7%) had moderate to severe depression, and participants aged 18 to 25 were found to have higher scores in PHQ-9. Changes in physical health and social contact were significantly associated with developing depressive symptoms. From the results, it is clear that the COVID-19 pandemic has the potential to exert a negative impact on the mental health status of individuals.

The potential impact of previous exposure to SARS or MERS on control of the COVID-19 pandemic.

The Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) is believed to share similar characteristics with SARS in 2003 and Mediterranean East Respiratory Syndrome (MERS) in 2012. We hypothesized that countries with previous exposure to SARS and MERS were significantly more likely to have fewer cases and deaths from coronavirus disease 2019 (COVID-19). We retrieved the incidence of COVID-19 per 100,000 population within 30 days since the first confirmed case was reported from the 2019 Novel COVID-19 data repository by the Johns Hopkins Centre for Systems Science and Engineering for 94 countries. The association between previous exposure to SARS and/or MERS and the 30-day COVID-19 incidence rate was examined by multivariable linear regression analysis, whilst controlling for potential confounders including the INFORM COVID-19 Risk Index, Testing Policies, Democracy Index, Scientific Citation Index, Gross Domestic Product (GDP), Human Development Index (HDI) and the population density of each country. We found that countries with previous exposure to SARS and/or MERS epidemics were significantly more likely to have lower incidence of COVID-19 (ß coefficient - 225.6, 95% C.I. - 415.8,- 35.4, p = 0.021). However, countries being classified as having "full democracy" using Democracy Index had higher incidence of COVID-19 (reference: authoritarian regime; ß coefficient 425.0, 95% C.I. 98.0, 752.0, p = 0.011). This implies that previous exposure to global epidemics and Democracy Index for a country are associated its performance in response to COVID-19. We recommend future studies should evaluate the impact of various pandemic control strategies at individual, community, and policy levels on mitigation of the disease.