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The Polio eradication campaign has been set back substantially since 2020 due to the COVID-19 pandemic. Recent detections of poliovirus transmission in multiple high-income countries suggest suboptimal population immunity in many parts of the world even though polio vaccination has been included in routine childhood immunization for decades. We reviewed polio vaccination schedules and vaccine uptake in the Western Pacific Region countries and assessed the potential shortfall in population immunity against polio resurgence across these populations. In addition, we conducted a repeated cross-sectional study between 2021 and 2022 in the Western Pacific Region to understand factors contributing to polio vaccine hesitancy. Our results reveal potential shortfalls in population immunity against polio in Western Pacific Region and provide insights into how vaccination programs and campaigns can be strengthened to ensure continual progress towards polio eradication.
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The SARS-CoV-2 Omicron variant has demonstrated enhanced transmissibility and escape of vaccine-derived immunity. While current vaccines remain effective against severe disease and death, robust evidence on vaccine effectiveness (VE) against all Omicron infections (i.e. irrespective of symptoms) remains sparse. We addressed this knowledge-gap using a community-wide serosurvey with 5,310 subjects by estimating how vaccination histories modulated risk of infection in Hong Kong (which was largely infection naive) during a large wave of Omicron epidemic during January-July 2022. We estimated that Omicron infected 45% (41-48%) of the Hong Kong population. Three and four doses of BNT162b2 or CoronaVac were effective against Omicron infection (VE of 47% (95% credible interval 34-68%) and 70% (43-99%) for three and four doses of BNT162b2 respectively; VE of 31% (1-73%) and 59% (10-99%) for three and four doses of CoronaVac respectively) seven days after vaccination, but protection waned with half-lives of 15 (3-47) weeks for BNT162b2 and 5 (1-37) weeks for CoronaVac. Our findings suggest that booster vaccination can temporarily enhance population immunity ahead of anticipated waves of infections.
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Both inactivated vaccine (CoronaVac; Sinovac) and mRNA vaccine (Comirnaty/BNT162b2; Fosun-Pharma/BioNTech) are available in Hong Kongs COVID-19 Vaccination Programme. We reported waning antibody levels by enzyme-linked immunosorbent assays (ELISA) and surrogate virus neutralization test (sVNT) among 850 fully vaccinated blood donors (i.e., received two doses). The BNT162b2 groups antibody levels remain over the 50% protection threshold within six months, and the CoronaVacs groups median antibody levels begin to fall below the 50% protection threshold two months after vaccination.
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BackgroundWe aimed to evaluate the impact of various allocation strategies of COVID-19 vaccines and antiviral such that the pandemic exit strategy could be tailored to risks and preferences of jurisdictions in the East Asia and Pacific region (EAP) to improve its efficiency and effectiveness. MethodsVaccine efficacies were estimated from the titre distributions of 50% plaque reduction neutralization test (PRNT50), assuming that PRNT50 titres of primary vaccination decreased by 2-10 folds due to antibody waning and emergence of VOCs, and an additional dose of vaccine would increase PRNT50 titres by 3- or 9-fold. We then used an existing SARS-CoV-2 transmission model to assess the outcomes of vaccine allocation strategies with and without the use of antivirals for symptomatic patients in Japan, Hong Kong and Vietnam. FindingsIncreasing primary vaccination coverage was the most important contributing factor in reducing the total and peak number of COVID-19 hospitalizations, especially when population vaccine coverage or vaccine uptake among older adults was low. Providing antivirals to 50% of symptomatic infections only further reduced total and peak hospitalizations by 10-13%. The effectiveness of an additional dose of vaccine was highly dependent on the immune escape potential of VOCs and antibody waning, but less dependent on the boosting efficacy of the additional dose. InterpretationIncreasing primary vaccination coverage should be prioritised in the design of allocation strategies of COVID-19 vaccines and antivirals in the EAP region. Heterologous vaccination with any available vaccine as the additional dose could be considered when planning pandemic exit strategies tailored to the circumstances of EAP jurisdictions. FundingHealth and Medical Research Fund, General Research Fund, AIR@InnoHK
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Hong Kong utilized an elimination strategy with intermittent use of public health and social measures and increasingly stringent travel regulations to control SARS-CoV-2 transmission. By analyzing >1700 genome sequences representing 17% of confirmed cases from 23-January-2020 to 26-January-2021, we reveal the effects of fluctuating control measures on the evolution and epidemiology of SARS-CoV-2 lineages in Hong Kong. Despite numerous importations, only three introductions were responsible for 90% of locally-acquired cases, two of which circulated cryptically for weeks while less stringent measures were in place. We found that SARS-CoV-2 within-host diversity was most similar among transmission pairs and epidemiological clusters due to a strong transmission bottleneck through which similar genetic background generates similar within-host diversity. One sentence summaryOut of the 170 detected introductions of SARS-CoV-2 in Hong Kong during 2020, three introductions caused 90% of community cases.
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Objective@#This study evaluated the validity of self-reported smartphone usage data against objectively-measured smartphone usage data by directly tracking the activities in the participants’ smartphone among Chinese adolescents and young adults in Hong Kong. @*Methods@#A total of 187 participants were recruited (mean age 19.4, 71.7% female) between 2017 and 2018. A smartphone usage tracking app was installed on all participants’ smartphone for 7 consecutive days. After the 7-day monitoring period, they completed a selfadministered questionnaire on smartphone usage habits. @*Results@#Although the correlation between self-reported and objectively-measured total smartphone usage time was insignificant (ρ=-0.10, p=0.18), in three out of the four usage domains were positively and significantly correlated, namely social network (ρ=0.21, p=0.005), instant messaging (ρ=0.27, p<0.001), and games (ρ=0.64, p<0.001). Participants’ self-report of the total time spent on smartphones exceeded the objective data by around 760 min per week (self-reported 1,930.3 min/wk vs. objectively-measured 1,170.7 min/wk, p<0.001). Most of the over-reporting was contributed by the web browsing domain (self-reported 447.8 min/wk vs. objectively-measured 33.3 min/wk, p<0.001). @*Conclusion@#Our results showed large discrepancies between self-reported smartphone and objectively-measured smartphone usage except for self-reported usage on game apps.
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Two new SARS-CoV-2 lineages with the N501Y mutation in the receptor binding domain of the spike protein have rapidly become prevalent in the UK. We estimated that the earlier 501Y lineage without amino acid deletion {Delta}69/{Delta}70 circulating mainly between early September to mid-November was 10% (6-13%) more transmissible than the 501N lineage, and the currently dominant 501Y lineage with amino acid deletion {Delta}69/{Delta}70 circulating since late September was 75% (70-80%) more transmissible than the 501N lineage.
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Digital proxies of human mobility and physical mixing have been used to monitor viral transmissibility and effectiveness of social distancing interventions in the ongoing COVID-19 pandemic. We developed a new framework that parameterizes disease transmission models with age-specific digital mobility data. By fitting the model to case data in Hong Kong, we were able to accurately track the local effective reproduction number of COVID-19 in near real time (i.e. no longer constrained by the delay of around 9 days between infection and reporting of cases) which is essential for quick assessment of the effectiveness of interventions on reducing transmissibility. Our findings showed that accurate nowcast and forecast of COVID-19 epidemics can be obtained by integrating valid digital proxies of physical mixing into conventional epidemic models.
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The SARS-CoV-2 lineage carrying the amino acid change D614G has become the dominant variant in the global COVID-19 pandemic. The rapid spread of the G614 mutant suggests that it may have a transmission advantage over the D614 wildtype. Using our previous epidemiological framework to analyze COVID-19 surveillance and sequence data, we estimated that the G614 mutant is 31% (28-34%) more transmissible than the D614 wildtype. As such, interventions that were previously effective in containing or mitigating the D614 wildtype (e.g. in China, Vietnam, Thailand, etc.) might be less effective against the G614 mutant. Our framework can be readily integrated into current COVID-19 surveillance to monitor the emergence and fitness of mutant strains, such that pandemic surveillance, disease control and development of treatment and vaccines can be adjusted dynamically.
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We analyze confirmed cases and new hospitalizations in Wisconsin in the weeks surrounding the April 7, 2020 election, and find no evidence of a surge in SARS-CoV-2 transmission.
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BackgroundA range of public health measures have been implemented to delay and reduce local transmission of COVID-19 in Hong Kong, and there have been major changes in behaviours of the general public. We examined the effect of these interventions and behavioral changes on the incidence of COVID-19 as well as on influenza virus infections which may share some aspects of transmission dynamics with COVID-19. MethodsWe reviewed policy interventions and measured changes in population behaviours through two telephone surveys, on January 20-23 and February 11-14. We analysed data on laboratory-confirmed COVID-19 cases, influenza surveillance data in outpatients of all ages, and influenza hospitalisations in children. We estimated the daily effective reproduction number (Rt), for COVID-19 and influenza A(H1N1). FindingsCOVID-19 transmissibility has remained at or below 1, indicating successful containment to date. Influenza transmission declined substantially after the implementation of social distancing measures and changes in population behaviours in late January, with a 44% (95% confidence interval, CI: 34% to 53%) reduction in transmissibility in the community, and a 33% (95% CI: 24% to 43%) reduction in transmissibility based on paediatric hospitalization rates. In the two surveys we estimated that 74.5% and 97.5% of the general adult population wore masks when going out, and 61.3% and 90.2% avoided going to crowded places, respectively. ImplicationsContainment measures, social distancing measures and changes in population behaviour have successfully prevented spread of COVID-19. The social distancing measures and behavioural changes led to a substantial reduction in influenza transmission in early February 2020. However, it may be challenging to avoid fatigue and sustain these measures and population behaviours as COVID-19 continues to spread globally. FundingHealth and Medical Research Fund, Hong Kong
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Family-based cohort study is a special type of study design, in which biological samples and environmental exposure information of the member in a family are collected and related follow up is conducted. Family-based cohort study can be applied to explore the effect of genetic factors, environmental factors, gene-gene interaction, and gene-environment interaction in the etiology of complex diseases. This paper summarizes the objectives, methods and results, as well as the opportunities and challenges of the family-based cohort study on common chronic non-communicable diseases in rural population in northern China.
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Femenino , Humanos , Masculino , Persona de Mediana Edad , China/epidemiología , Enfermedad Crónica/etnología , Estudios de Cohortes , Interacción Gen-Ambiente , Enfermedades no Transmisibles/etnología , Proyectos de Investigación , Población RuralRESUMEN
Non-syndromic oral clefts (NSOC) are among the most common birth defects. The prevalence of NSOC is 1.13-1.30 per 1 000 live births in China, which is higher than those in other major ethnic groups. The etiology of NSOC is complex and heterogeneous, which involves both genetic and environmental risk factors. Although genome-wide association studies have identified a number of risk loci, these loci can only account for a small proportion of the heritability of NSOC. The next-generation sequencing research provides new ideas for further exploring the genetic risk factors of NSOC. This paper summaries the progress in the next-generation sequencing research of NSOC.
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Humanos , Pueblo Asiatico/genética , China , Labio Leporino/genética , Fisura del Paladar/genética , Etnicidad/genética , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Secuenciación de Nucleótidos de Alto Rendimiento , Polimorfismo de Nucleótido SimpleRESUMEN
Objective: To investigate the risks of pre-pregnancy overweight, excessive gestational weight gain on macrosomia. Methods: We conducted one hospital-based cohort study, focusing on pregnant women from January 2015. All pregnant women attending to this hospital for maternal check-ups, were included in our cohort and followed to the time of delivery. Data related to general demographic characteristics, pregnancy and health status of those pregnant women, was collected and maternal pre-pregnant BMI and maternal weight gain were calculated. Logistic regression was used to explore the risk difference of pre-pregnancy BMI, excessive gestational weight gain on macrosomia. Results: The overall incidence of macrosomia in our cohort appeared as 6.6% (149/2 243). After adjusting the confounding factors including age and histories on pregnancy, pre-pregnancy overweight/obesity was associated with higher risks of macrosomia (OR=3.12, 95%CI: 1.35-7.22, P=0.008; OR=2.99, 95%CI: 1.17-7.63, P=0.022) when comparing to those with normal pre-pregnancy weight. Cesarean delivery and sex of the offspring were associated with higher risk of macrosomia, while excessive gestational weight gain showed no significant difference (OR=1.41, 95%CI: 0.96-2.09, P=0.084). Our data showed that Macrosomia was statistically associated with gestational weight gain (P=0.002). After controlling parameters as age, history of pregnancy and related complications of the pregnant women, results from the logistic regression showed that women with gestational inadequate weight gain having reduced risks to deliver macrosomia, when compared to those pregnant women with adequate weight gain (OR=0.52, 95%CI: 0.30-0.90, P=0.019). Conclusion: Pre-pregnancy overweight and obesity were on higher risks to macrosomia.
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Femenino , Humanos , Embarazo , Índice de Masa Corporal , Cesárea/estadística & datos numéricos , China/epidemiología , Macrosomía Fetal/epidemiología , Incidencia , Modelos Logísticos , Obesidad/epidemiología , Sobrepeso/epidemiología , Complicaciones del Embarazo/epidemiología , Estudios Prospectivos , Aumento de PesoRESUMEN
Objective: To describe the study design, the characteristics of participants as well as the pedigrees included in the baseline survey of Fujian Tulou Family Cohort Study. Methods: Fujian Tulou Family Cohort Study was a prospective open cohort study with a biological sample bank. A baseline survey was conducted in Tulou areas of Nanjing county in Fujian province from 2015 to 2018, including questionnaire survey, physical and biochemical indicators examinations, and blood sample collection in adults aged ≥18 years. In addition, family relationship of the participants was also recorded. The pedigree information of the juveniles under 18 years old were also collected. Results: The baseline survey included 2 727 individuals in two clans, of whom 2 373 (87.0%) were adults, and 2 126 participants completed questionnaires, physical examinations and biochemical tests. The average age of the 2 126 participants was (57.9±13.3) years, with 39.4% being males. The current smoking rates in male and female participants were 41.2% and 2.1%, respectively. The corresponding rates of current alcohol consumption were 19.0% and 2.6%. For common chronic diseases, the prevalence rates were 51.3% for hypertension, 9.7% for diabetes and 26.7% for hyperlipemia according to the self-reported disease diagnoses, health examination results and biochemical examination results in class Ⅱ or Ⅲ hospitals. Based on the family relationship information and genealogical data, 710 pedigrees were finally identified, consisting of 5 087 family members. The numbers of five, four, three, and two generations pedigrees were 3, 88, 238 and 381, respectively. The pairs of the first to the fifth degree relatives were 12 039, 2 662, 1 511, 202 and 31, respectively. Conclusion: The establishment of Fujian Tulou Family Cohort provides valuable resources for exploring the genetic risk factors, environmental risk factors and gene-environment interactions contributing to the risk of common chronic diseases.
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Adolescente , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , China/epidemiología , Enfermedad Crónica/etnología , Estudios de Cohortes , Diabetes Mellitus/etnología , Salud de la Familia , Interacción Gen-Ambiente , Predisposición Genética a la Enfermedad/etnología , Hiperlipidemias/etnología , Hipertensión/etnología , Linaje , Estudios Prospectivos , Factores de Riesgo , Encuestas y CuestionariosRESUMEN
ABSTRACT Bed samples of the Amazon River were collected from Iquitos (Peru) to Belém (Brazil). 28 selected samples were analysed and 12 types of heavy minerals were found: tourmaline, zircon, garnet, staurolite, hypersthene, pyroxene (augite), amphibole (hornblende), tremolite, magnetite or ilmenite and leucoxene. Most of the samples presented large amount of idiomorphic unstable minerals such as hypersthene, augite and amphibole pointing towards basic and ultra-basic rocks source. These unstable minerals diminish toward the lower portion of the river. Stable minerals such as zircon and tourmaline have showed both angular and round shapes, which indicate more than one source but in any case originating from acid rocks. A cluster analysis method was applied to the data and two main clusters were determined. The first group, located at the upper Amazon River, is rich in unstable minerals, probably from an Andean source. The second group, which includes samples located below the confluence of the Juruá River, presents a high zircon and tourmaline percentage which indicates a contribution from the Precambrian Shields in adition to the Andean source.
Resumo Com a intenção de verificar a origem do material transportado pelo Rio Amazonas, amostras de calha foram coletadas em 60 locais entre Belém (Brasil) até Iquitos (Peru). Tendo sido escolhidos 28 amostras, as mesmas foram submetidas a um estudo mineralógico, o qual revelou os seguintes minerais pesados presentes: turmalina, zircão, granada, estaurolita, hiperstênio, piroxênio (augita), anfibólio (hornblenda), tremolita, magnetita ou ilmenita e leucoxênio. Em quase todas as amostras ocorre uma grande quantidade de minerais instáveis idiomórficos, como hiperstênio, augita e anfibólio, indicando uma área fonte constituída pelas rochas básicas e ultrabásicas, diminuindo para jusatite. Minerais estáveis, como zircão e turmalina, apresentam-se tanto angulosos como arredondados, indicando mais de uma área fonte, mas de qualquer modo sempre a partir de rochas ácidas. Aplicando aos dados o método classificatório multivariante da análise de agrupamentcs (cluster analysis), dois maiores grupos de amostras foram ressaltados: um constituído por amostras localizadas no alto Rio Amazonas e com maior teor em minerais instáveis, provavelmente com origem andina; o outro formado principalmente por amostras que se localizam, a partir da confluência com o Rio Juruá, até Belém e contendo uma alta porcentagem em zircão e turmalina, indicando além de uma contribuição andina, fontes nos escudos precambrianos a norte e sul do Rio Amazonas.
