Re-examine the transfusion transmitted risk of SARS-CoV-2 virus during a major COVID-19 outbreak in 2022.

INTRODUCTION: Although no case of COVID-19 transmission through transfusion has been reported, blood transfusion service (BTS) continues to implement pre-donation and post-donation measures to minimise the risk. In year 2022, when local healthcare system was badly impacted by a major outbreak, it opened an opportunity to re-examine the viraemia risk in these asymptomatic donors. MATERIALS AND METHODS: Records were retrieved from blood donors who reported COVID-19 after donation and follow-up was also made for recipients who received their blood. Blood samples at donation were tested for SARS-CoV-2 viraemia by single-tube nested real-time RT-PCR assay designed to detect most SARS-CoV-2 variants including the prevailing delta and omicron variants. RESULTS: From 1 January to 15 August 2022, the city with 7.4 M inhabitants recorded 1 187 844 COVID-19 positive cases and 125 936 successful blood donations were received. 781 donors reported to the BTS after donation with 701 being COVID-19 related (including close contact and symptoms respiratory tract infection). 525 COVID-19 were positive at the time of call back or follow-up. Of the 701 donations, they were processed into 1480 components with 1073 discarded upon donors' call back. For remaining 407 components, no recipient was found to have adverse event or COVID-19 positive. 510 samples from the above 525 COVID-19 positive donors were available and all tested negative for SARS-CoV-2 RNA. DISCUSSION: With the negative SARS-CoV-2 RNA in blood donation samples and follow up data in transfusion recipients, the risk of transfusion transmitted COVID-19 appears negligible. However, current measures remains important in securing blood safety with ongoing surveillance of their effectiveness.

Evaluation of a nutrition education and cooking programme (NEST) in vulnerable adults who are at high risk of food insecurity

Within Australia, the prevalence of food insecure individuals increased from 2.6 million in 2014-2016 (10.8%) to 3.1 million in 2018- 2020 (12.3%) due to the COVID-19 pandemic.(1) OzHarvest is a not-for-profit organisation that prioritises food salvaging, food waste prevention and nutrition education.(2) OzHarvest's education sector facilitates a programme known as Nutrition Education Skills Training (NEST). NEST is a 6-week programme providing weekly workshops of 2.5-hour duration offering skills training on cooking simple, healthy, and affordable meals to adults at risk of food insecurity. This study aimed to determine the immediate and longerterm impacts of participation in NEST. A quasi-experimental study with pre-post surveys (n = 258) and follow-up surveys (n = 20) was conducted from June 2019 to July 2022. Survey results were obtained from NEST program participants (18 years) from Adelaide Canberra, Melbourne, Newcastle, Queensland, and Sydney. Baseline (pre-) and post-surveys (at program completion) were administered to participants, with an option for a 6-month follow-up survey. Participants were required to complete both surveys to be eligible for this study. Questionnaires included 23 core questions adapted from previous studies,(3) allowing evaluation of nutrition knowledge confidence and self-efficacy, shopping, and food preparation behaviours, and eating behaviours. Food security was assessed using the standard 6-item indicator set for classifying households by food security status level. Using paired t-tests, Shapiro Wilks, and Wilcoxon sign-ranked tests for pre and post survey data, participants demonstrated overall improvement in nutrition knowledge (p < 0.001), confidence and self-efficacy (n = 222;p < 0.001) and food preparation behaviours (p < 0.001). The intake of discretionary foods overall decreased (p < 0.001) while fruit, vegetable and water intake increased (p < 0.001). Food security improved from 57% to 68% immediately within the population (p < 0.001). Using RMANOVA and Shapiro Wilks tests, the 6-month survey results were compared to the pre surveys suggested longer lasting improvements in nutrition knowledge (p < 0.001), cooking confidence (n = 8;p = 0.033), food preparation behaviours (p = 0.003), and increased vegetable intake (p = 0.032) and fruit intake (p = 0.012) Participation in OzHarvest's NEST programme results in short-term improvements in food security levels and dietary behaviours Over the longer term, these changes were sustained but to a lesser degree, indicating that systemic changes are required to address underlying socioeconomic disadvantage.

Pharm Aco Kin Etics, Safety, and Tolerability of Upadacitinib in Children with Atopic Dermatitis

BACKGROUND: Upadacitinib is a Janus kinase inhibitor that has been approved for the treatment of adults and adolescents with moderate to severe atopic dermatitis (AD). The objective of this study was to characterize the pharmacokinetics (PK), safety, and tolerability of upadacitinib in children with severe atopic dermatitis. METHOD(S): This is an open-label, multiple-dose study. AD patients (n = 35) were enrolled into four cohorts (Cohort 1, 6 to <12 years, low dose;Cohort 2, 6 to <12 years, high dose;Cohort 3, 2 to <6 years, low dose;Cohort 4, 2 to <6 years, high dose). The low and high doses were selected based on body weight to provide comparable plasma exposure in pediatrics to 15 mg and 30 mg QD doses in adults, respectively. All patients continued on the low dose after the PK assessment on Study Day 7. Safety and exploratory efficacy parameters are assessed in the study. RESULT(S): Geometric mean Cmax and AUC over 0-24 hours at steady state were 33.1 ng/mL and 249 ng.h/mL, respectively, in Cohort 1, 95.5 ng/mL and 523 ng.h/mL, respectively, in Cohort 2, 35.2 ng/mL and 264 ng.h/mL, respectively, in Cohort 3, and 101 ng/mL and 625 ng.h/mL, respectively, in Cohort 4. Upadacitinib was generally safe and well tolerated. The most common AEs were COVID infection, headache, and abdominal discomfort. No new safety risks were identified compared to the known safety profile for upadacitinib. In the 29 subjects with available interim efficacy results at week 12, 34.5% achieved validated Investigator's Global Assessment scale for AD score of 0 or 1 and 69.0% achieved Eczema Area and Severity Index by at least 75% at Week 12 with treatment of upadacitinib. CONCLUSION(S): The findings supported the use of current dosing regimens for further investigation of upadacitinib in upcoming phase 3 clinical trials in pediatric AD patients.

Investigating the motivations and preferences of Chinese cruise travelers amid COVID-19. (Special Issue: Tourism recovery under COVID-19: Experiences from China.)

The literature on cruise tourism is primarily Western-focused, which could differ compared to those in Asia Pacific. To address this gap, this study combines motivation and cruise preferences for a better understanding of repeated Chinese cruisers amid COVID-19 via the use of conjoint and cluster analysis. The findings revealed that shore activity is more important than cabin price and duration. Sight-seeing is the most strongly preferred shore excursion, followed by visiting natural scenery. This study contributes by providing insight into the current views of the Chinese travel market, and provides suggestions to cruise companies on target segments, product design, and marketing strategies in preparation for travel recovery.

Cruise revenue management: cross-discipline literature review and development of an integrated cruise revenue management framework

Purpose: This study aims to adopt a holistic approach to understand cruise revenue management (RM) practices that cover ticket and onboard revenues, through a cross-disciplinary literature review and practitioner interviews. An integrated cruise RM framework was developed and served as a blueprint for future cruise studies and practices. Design/methodology/approach: A multi-stage approach was adopted, including a systematic literature review, two-waves of interviews with 26 cruise industry practitioners and the development of a holistic RM framework. Findings: This study clarifies cruise RM functions across product planning, delivery stages and identifies ticket and onboard RM components. These are incorporated into the integrated framework, with weather and itinerary/ route attractiveness as additional considerations. Interviews revealed that there is no difference in the RM cycle before and during the COVID-19 pandemic, although strategies and tactics may vary in response to the market situation. Research limitations/implications: Suggestions are made regarding product and service bundling and ways for ticket and onboard revenue teams to work together to optimize total revenue. Future research directions are also provided under the categories of RM applications and concepts, ticket core activities, onboard core activities and overall issues. Originality/value: To the best of the authors' knowledge, this is the first paper to conduct a cross-disciplinary systematic literature review of cruise RM without imposing publication dates or specific databases and the first to develop an integrated cruise "total” RM framework that includes ticket and onboard revenues. © 2023, Emerald Publishing Limited.

COVID-19 Vaccination Strategies in Solid Organ Transplant Recipients: A Living Systematic Review and Network Meta-Analysis

The optimal COVID-19 vaccination strategy in solid organ transplant recipients (SOTRs) remains unclear. We conducted a living systematic review and network meta-analysis (NMA) to explore COVID-19 vaccination strategies in SOTRs. We conducted a search of databases from inception to July 2022 for all studies comparing any COVID-19 vaccination strategy in SOTRs. We performed a NMA to evaluate the impact of various vaccination strategies on COVID-19 infection, and COVID-related mortality. We used the GRADE approach for NMA to judge our certainty in the evidence. Of 2,534 publications identified, 27 proved eligible (4 RCTs, 23 observational). Identified RCTs were only subject to narrative summarization due to heterogeneity in their research questions (Figure A). Nine observational studies (76,703 SOTRs, 6.3% heart transplant, 5.2% lung transplant) reported adjusted hazard ratios (HRs) for COVID-19 infection and/or COVID-related mortality. The NMA for the impact of various doses of vaccines on COVID-19 infection suggested a dose-response relationship (Figure B). Compared to no vaccination, three (HR 0.16, 95%CI 0.11-0.22, moderate certainty) or two (HR 0.45, 95%CI 0.35-0.58, moderate certainty) doses of any COVID-19 vaccine showed a strong effect on reducing COVID-19 infection. One dose showed a moderate effect (HR 0.73, 95%CI 0.49-1.07, low certainty) on reducing COVID-19 infection. Two doses of any vaccine showed a moderate effect on lowering risk of mortality in COVID-19 infected SOTRs (HR 0.74, 95%CI 0.63-0.89, low certainty). We did not identify sufficient data to explore effect modification by organ group or immunosuppressant use. Current evidence suggests that increasing the number of COVID-19 vaccination doses may provide increasing protection against COVID-19 infection in SOTRs (moderate to low certainty). Further studies are needed to better understand the impact of COVID-19 vaccination on all patient-important outcomes. [ABSTRACT FROM AUTHOR] Copyright of Journal of Heart & Lung Transplantation is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

COVID-19 catalyst: emergent pedagogies and a DIAgram framework

The global COVID-19 pandemic has delivered extraordinary challenges across geographies as well as practices, and clearly academia has not been spared. While the events of 2020 and 2021 have revealed some limits to teaching in the `old (pre-pandemic) normal', technology-supported pedagogies have been emerging for several years. This pandemic has been a potent catalyst, not only for ad-hoc adaptation, but potentially for long-term change and improvement. The `old normal' is now long passed, and approaches to learning and teaching continue to explore new ground. This article draws on the work of Built Environments Learning + Teaching (BEL+T), an academic group within the Faculty of Architecture, Building and Planning at the University of Melbourne. The BEL+T group applies creative problem-solving and design-led approaches, evidence-based research methodologies and project-focused consultancy to improve teaching quality and student engagement in built environment disciplines. The following sections introduce a learning design framework - the Delivery, Interaction, Assessment (DIA) framework - which was developed by BEL+T as a tool to communicate with and support staff throughout 2020 and 2021, and continues to be used to support teaching efforts. The translation of the elements of the DIA framework and its related `DIAgram' to specific learning activities are presented in the following sections `on the (virtual) ground'. Some emergent pedagogies for virtual learning environments (VLEs) are outlined, exploring relationships between students, teachers, objects, sites and VLEs for learning, alongside implications for teacher presence and performance online. These key factors have influenced online approaches both before and since the onset of the pandemic. They deliver implications for emergent hybrid approaches such as dual delivery and blended synchronous learning, which are in turn driven by the needs of a still-distributed student cohort and the challenges of ongoing unpredictability.

Technology Acceptance Before and After Covid Pandemic

The purpose of this study is to investigate factors that influence learners’ intention towards accepting online learning tools before and after Covid pandemic in different learning environments. A total of 350 sample collected prior to Covid pandemic in Malaysia whereas 627 sample collected at post Covid pandemic in China. UTAUT model and TAM served as the frameworks whereas PLS-SEM was used for data analysis. The findings disclosed that both Performance Expectancy and Effort Expectancy have positive relationship with students’ Behavioral Intention of accepting online learning tools in the Malaysia’s study before Covid pandemic under the blended learning environment. However, the effect size (f2) of Performance Expectancy is small (f2 = 0.020), and Effort Expectancy has no effect (f2 = 0.015) in predicting Behavioral Intention in adopting online learning tools. While comparing to another similar study conducted in China after covid pandemic in the mobile learning environment, Performance Expectancy (perceived usefulness) has large effect size (f2 = 0.403), and Effort Expectancy (ease of use) has medium effect size (f2 = 0.241) on students’ adoption of online learning technologies. By comparing results of the two studies, the effect size of Performance Expectancy increased from small to large effect, while Effort Expectancy increased from no effect to medium effect. This shows that the widespread of Covid pandemic has impacted the learning approaches in education institutions likewise the perception of students towards technology acceptance. Importance-performance matrix analysis was used as a post-hoc procedure to measure the importance and performance of the exogenous constructs for both studies. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.

US Evaluation of Axillary Lymphadenopathy Following COVID-19 Vaccination: A Prospective Longitudinal Study.

Background Both temporal changes in imaging characteristics of lymphadenopathy on US scans after COVID-19 vaccination and expected duration of radiologically evident lymphadenopathy remain uncertain. Purpose To longitudinally evaluate COVID-19 vaccine-associated lymphadenopathy on axillary US scans at various time intervals in both messenger (mRNA) and vector vaccine recipients. Materials and Methods This prospective cohort study was conducted between March 2021 and January 2022. The participants were asymptomatic women without breast cancer who had received COVID-19 vaccination. Serial follow-up US was performed in women with lymphadenopathy. The following variables were assessed: cortical thickness, number of lymph nodes, morphologic characteristics, and Doppler signal. Temporal changes in cortical thickness and number of lymph nodes during follow-up were assessed using a linear mixed model. Results Ninety-one women with lymphadenopathy in the vaccinated arm had undergone a total of 215 serial US examinations (mean age, 44 years ± 13 [SD]). Fifty-one participants had received a vector vaccine (ChAdOx1 nCoV-19 vaccine) and 40 had received an mRNA vaccine (BNT162b2 vaccine [n = 37] and mRNA-1273 vaccine [n = 3]). Three of the 91 women were lost to follow-up; thus, 88 women underwent serial US. Complete resolution of axillary lymphadenopathy was observed at a median of 6 weeks after vaccination (range, 4-7 weeks) in 26% of women (23 of 88). Among 49 women with follow-up US at a median of 12 weeks after vaccination (range, 8-14 weeks), persistent lymphadenopathy was observed in 25 (51%). During the follow-up period, the cortical thickness gradually decreased (P < .001) over time regardless of vaccine type; however, values were higher in recipients of the mRNA vaccine than in recipients of the vector vaccine (P = .02). Conclusion COVID-19 vaccine-associated axillary lymphadenopathy frequently persisted for more than 6 weeks on US scans. Lymphadenopathy should be interpreted considering vaccine type and time elapsed since vaccination. Follow-up US examination at least 12 weeks after vaccination may be reasonable, particularly for recipients of the messenger RNA vaccine. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Moy and Kim in this issue.

Factors Influencing Elementary Teachers’ Readiness in Delivering Sex Education amidst Covid-19 pandemic

The emergence of variants of Covid-19, the persistence of lockdowns in many countries, and the necessity to maintain sustainable education have resulted in a shift from the traditional classroom to virtual space. As such, there is a strong need to leverage technological advances while mitigating the challenges faced by primary teachers. Through the incorporation of eight elements, the authors sought to better understand factors that influence teacher readiness to deliver sex education in primary schools. Structural Equation Modeling was employed to assess the proposed conceptual model. The online survey was designed and distributed by Google Forms. Based on the results from 383 individuals, the findings revealed that facilitating conditions, educational policy, and parental involvement all had a relationship with teacher readiness. Digital content positively influenced performance expectancy and effort expectancy. Sexual knowledge had a statistically significant and positive influence on effort expectancy. Finally, openness had a statistically significant and positive influence on performance expectancy. The significant exceptions were that effort expectancy was not found to predict teacher readiness, and performance expectancy was not found to influence teacher readiness. The reasons for these non-significant correlations were briefly discussed and more studies on this topic are called to investigate these unexpected outcomes in more detail. The level of readiness, as well as theoretical and practical implications for scholars and practitioners, were discussed. ©Authors

COVID-19's U.S. Temperature Response Profile.

We estimate the U.S. temperature response profile (TRP) for COVID-19 and show it is highly sensitive to temperature variation. Replacing the erratic daily death counts U.S. states initially reported with counts based on death certificate date, we build a week-ahead statistical forecasting model that explains most of their daily variation (R2 = 0.97) and isolates COVID-19's TRP (p < 0.001). These counts, normalized at 31 °C (U.S. mid-summer average), scale up to 160% at 5 °C in the static case where the infection pool is held constant. Positive case counts are substantially more temperature sensitive. When temperatures are declining, dynamic feedback through a growing infection pool can substantially amplify these temperature effects. Our estimated TRP can be incorporated into COVID-related planning exercises and used as an input to SEIR models employed for longer run forecasting. For the former, we show how our TRP is predictive of the realized pattern of growth rates in per capita positive cases across states five months after the end of our sample period. For the latter, we show the variation in herd immunity levels implied by temperature-driven, time-varying R0 series for the Alpha and Delta variants of COVID-19 for several representative states. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10640-021-00603-8.

The Impact of the COVID-19 on the Construction Industry in Vietnam

The COVID-19 pandemic has generated a wide range of socio-economic disruption, which causes devastating in numerous aspects. Our knowledge of the true health of the construction industry under the ravage of COVID-19 outbreak is largely based on very limited data. This study aims to assess the impact of pandemic on the construction industry through an investigation in Vietnam. Data were collected through 129 respondents whose online questionnaire survey completed according to their recent direct or indirect participation in delivering construction projects during the spread. The implications of COVID-19 on the construction industry were examined based on simple percentage analysis and Relative Importance Index approaches. Three principal facets of the construction industry were considered: firms' business activities, project performance, and workforce demand. The findings highlighted the multilevel, multidimensional nature of the epidemic consequences on the construction sector. Notably, the revenue and profitability, in a general sense, have decreased during the COVID-19 period, while most of the production and business costs had remained unchanged. Further, the pandemic was argued to impair construction practitioners' incomes and mental health and sabotage projects' schedule and cost. (C) 2021 Penerbit UTM Press. All rights reserved

Evaluation of an Automated High-Throughput Liquid-Based RNA Extraction Platform on Pooled Nasopharyngeal or Saliva Specimens for SARS-CoV-2 RT-PCR

SARS-CoV-2 RT-PCR with pooled specimens has been implemented during the COVID-19 pandemic as a cost- and manpower-saving strategy for large-scale testing. However, there is a paucity of data on the efficiency of different nucleic acid extraction platforms on pooled specimens. This study compared a novel automated high-throughput liquid-based RNA extraction (LRE) platform (PHASIFY TM) with a widely used magnetic bead-based total nucleic acid extraction (MBTE) platform (NucliSENS^R easyMAG^R). A total of 60 pools of nasopharyngeal swab and 60 pools of posterior oropharyngeal saliva specimens, each consisting of 1 SARS-CoV-2 positive and 9 SARS-CoV-2 negative specimens, were included for the comparison. Real-time RT-PCR targeting the SARS-CoV-2 RdRp/Hel gene was performed, and GAPDH RT-PCR was used to detect RT-PCR inhibitors. No significant differences were observed in the Ct values and overall RT-PCR positive rates between LRE and MBTE platforms (92.5% (111/120] vs. 90% (108/120]), but there was a slightly higher positive rate for LRE (88.3% (53/60]) than MBTE (81.7% (49/60]) among pooled saliva. The automated LRE method is comparable to a standard MBTE method for the detection of SAR-CoV-2 in pooled specimens, providing a suitable alternative automated extraction platform. Furthermore, LRE may be better suited for pooled saliva specimens due to more efficient removal of RT-PCR inhibitors.

The causal effects of chronic air pollution on the intensity of COVID-19 disease: Some answers are blowing in the wind (preprint)

The threats posed by COVID-19 have catalyzed a search by researchers across multiple disciplines for policy-relevant findings about critical risk factors. We contribute to this effort by providing causal estimates of the link between increased chronic ambient pollutant concentrations and the intensity of COVID-19 disease, as measured by deaths and hospitalizations in New York City from March through August, 2020. Given concerns about unobservable characteristics that contribute to both ambient air pollutant concentrations and the impacts of COVID-19 disease, we instrument for pollutant concentrations using the time spent downwind of nearby highways and estimate key causal relationships using two-stage least squares models. The causal links between increases in concentrations of our traffic-related air pollutants (PM2.5, NO2, and NO) and COVID-19 deaths are much larger than the correlations presented in recent observational studies. We find that a 0.16 g/m3 increase in average ambient PM2.5 concentration leads to an approximate 30% increase in COVID-19 deaths. This is the change in concentration associated with being downwind of a nearby highway. We see that this effect is mostly driven by residents with at least 75 years of age. In addition to emphasizing the importance of searching for causal relationships, our analysis highlights the value of increasing the density of pollution-monitoring networks and suggests potential benefits of further tightening of Clean Air Act amendments, as our estimated effects occur at concentrations well below thresholds set by the National Ambient Air Quality Standards.

Weathering the storm: Viet Nam’s legal and policy measures in the time of COVID-19

The novel coronavirus has shaken the entire world to its roots. Yet, governments’ responses have taken many forms. Some countries were able to flatten the curve, while others struggled to pick up the pieces. This article provides governance implications drawn from Viet Nam’s COVID-19 experience. Accordingly, the country’s key features of its COVID-19 responses include resolute leadership, information transparency, central – local government coordination, public participation, and adequate preparedness. Besides, this article also highlights some of Viet Nam’s key legislative and policy initiatives in a bid to cautiously keep the pandemic under control and the economy rolling. By doing so, it makes a practical contribution to the discourse on public governance in the time of a public health emergency. © 2020 National Research University Higher School of Economics. All rights reserved.

Managing hotel revenue amid the COVID-19 crisis

Purpose - The revenue management (RM) discipline is built on the principle of demand-based pricing. This study aims to examine how and to what extent RM can be implemented in the hotel industry during low-demand periods, particularly during the coronavirus disease 2019 (COVID-19) crisis. Design/methodology/approach - This paper used semi-structured interviews to gather information from hotel RM executives, RM consultants and RM system providers. Participants were asked to think about the impact of COVID-19 on their RM practices. This paper interviewed 26 revenue executives between January and March 2020. Findings - Core RM processes are still relevant during the COVID-19 crisis;however, not all components are equally important. Business analysis, pricing strategy and demand modeling and forecasting are the most critical RM processes. Inventory and price optimization and setting booking controls are not as important at this time;along with distribution channel management, these processes will become more relevant as demand picks up. Research limitations/implications - Future research in this area should focus on each core RM process separately and in-depth to understand how implementation changes during the crisis and recovery periods. Future studies should also investigate how these processes operate during the recovery period. The full breadth of consequences of the COVID-19 crisis in hotel RM will likely manifest gradually. Therefore, the core RM processes should also be examined when the crisis is over. Originality/value - Apart from a few studies that touched on RM-related strategies during economic downturns, to the knowledge, this is the first study to systematically examine the extent to which RM can be implemented during a crisis.

Impacts of the COVID-19 pandemic on financial market connectedness

In this paper, we study the impacts of the COVID-19 pandemic on the connectedness of the Hong Kong financial market. We construct dynamic financial networks based on correlations and partial correlations of stock returns to assess the impacts of COVID-19 and to compare the impacts in the previous financial crises in the past 15 years. Compared to other crises where the network density and clustering can be explained by co-movement with market indices as in normal periods, both network density and clustering are higher in the partial correlation networks during the COVID-19 outbreak. © 2020 Elsevier Inc.

COVID-19's U.S. Temperature Response Profile (preprint)

We estimate the U.S. temperature response curve for COVID-19 and show transmission is quite sensitive to temperature variation. This is despite summer outbreaks widely assumed to show otherwise. By largely replacing the death counts states report daily, with counts based on death certificate date, we build a week-ahead statistical forecasting model that explains most of the daily variation (R-square = 0.97) and isolates the COVID-19 temperature response profile (p < 0.001). These counts normalized at 31C (U.S. mid-summer average) scale up nearly 160% at 5C. Positive cases are more temperature sensitive; scaling up by almost 400% between 31C and 5C. Dynamic feedback amplifies these effects. There is a short window to get COVID-19 under control before cooler weather makes the task substantially more challenging.