Sequential Administration of SARS-CoV-2 Strains-Based Vaccines Effectively Induces Potent Immune Responses against Previously Unexposed Omicron Strain.

In the past few years, the continuous pandemic of COVID-19 caused by SARS-CoV-2 has placed a huge burden on public health. In order to effectively deal with the emergence of new SARS-CoV-2 variants, it becomes meaningful to further enhance the immune responses of individuals who have completed the first-generation vaccination. To understand whether sequential administration using different variant sequence-based inactivated vaccines could induce better immunity against the forthcoming variants, we tried five inactivated vaccine combinations in a mouse model and compared their immune responses. Our results showed that the sequential strategies have a significant advantage over homologous immunization by inducing robust antigen-specific T cell immune responses in the early stages of immunization. Furthermore, the three-dose vaccination strategies in our research elicited better neutralizing antibody responses against the BA.2 Omicron strain. These data provide scientific clues for finding the optimal strategy within the existing vaccine platform in generating cross-immunity against multiple variants including previously unexposed strains.

Research on urban country parks based on emergency medical facilities for public health emergencies-a case study of Guangzhou, China.

As COVID-19 has swept across the world, the escalating number of confirmed and suspected cases overwhelmed the admission capacity of the designated hospitals. Faced with such a grim situation, governments made a quick decision to build emergency medical facilities to address the outbreak. However, the emergency medical facilities faced a huge risk of epidemic spread and improper site could lead to serious secondary transmission. Using the disaster prevention and risk avoidance function of urban green space can solve the problem of selecting the location of emergency medical facilities to a certain extent, with country parks having a high degree of compatibility with the latter. Based on the location requirements of emergency medical facilities, using Analytic Hierarchy Process and Delphi method, through analyzing the type of country parks, effective risk avoidance area, spatial fragmentation, distance from water sources, wind direction, and distance from the city, quantification of 8 impact factors such as hydrogeology and traffic duration was conducted to comprehensively compare 30 country parks in Guangzhou. The results showed that the overall quality of country parks approximated a normal distribution, with Lianma Forest Country Park having the highest comprehensive score and the most balanced distribution of scores for various impact factors. Considering safety, expandability, rehabilitation, convenience, pollution prevention, and fecal isolation, it is a preferred destination for emergency medical facility construction.

Impact of comorbidities on the serological response to COVID-19 vaccination in a Taiwanese cohort.

BACKGROUND/AIMS: Vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is one of the best policies to control COVID-19 pandemic. The serological response to COVID-19 vaccination in Taiwanese patients with different comorbidities is elusive. METHODS: Uninfected subjects who received 3 doses of mRNA vaccines (BNT162b2 [Pfizer-BioNTech, BNT] and mRNA-1273 [Moderna]), viral vector-based vaccines (ChAdOx1-S (AZD1222, AZ) or protein subunit vaccines (Medigen COVID-19 vaccine) were prospectively enrolled. The SARS-CoV-2-IgG spike antibody level was determined within three months after the 3rd dose of vaccination. The Charlson Comorbidity Index (CCI) was applied to determine the association between vaccine titers and underlying comorbidities. RESULTS: A total of 824 subjects were enrolled in the current study. The proportions of CCI scores of 0-1, 2-3 and > 4 were 52.8% (n = 435), 31.3% (n = 258) and 15.9% (n = 131), respectively. The most commonly used vaccination combination was AZ-AZ-Moderna (39.2%), followed by Moderna-Moderna-Moderna (27.8%). The mean vaccination titer was 3.11 log BAU/mL after a median of 48 days after the 3rd dose. Factors associated with potentially effective neutralization capacity (IgG level ≥ 4160 AU/mL) included age ≥ 60 years (odds ratio [OR]/95% confidence interval [CI]: 0.50/0.34-0.72, P < 0.001), female sex (OR/CI: 1.85/1.30-2.63, P = 0.001), Moderna-Moderna-based vaccination (compared to AZ-AZ-based vaccination, OR/CI: 6.49/3.90-10.83, P < 0.001), BNT-BNT-based vaccination (compared to AZ-AZ-based vaccination, OR/CI: 7.91/1.82-34.3, P = 0.006) and a CCI score ≥ 4 (OR/CI: 0.53/0.34-0.82, P = 0.004). There was a decreasing trend in antibody titers with increasing CCI scores (trend P < 0.001). Linear regression analysis revealed that higher CCI scores (ß: - 0.083; 95% CI: - 0.094-0.011, P = 0.014) independently correlated with low IgG spike antibody levels. CONCLUSIONS: Subjects with more comorbidities had a poor serological response to 3 doses of COVID-19 vaccination.

Characterization of RBD-specific cross-neutralizing antibodies responses against SARS-CoV-2 variants from COVID-19 convalescents.

Introduction: The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has been posing a severe threat to global public health. Although broadly neutralizing antibodies have been used to prevent or treat corona virus disease 2019 (COVID-19), new emerging variants have been proven resistant to these antibodies. Methods: In this study, we isolated receptor binding domain (RBD)-specific memory B cells using single-cell sorting method from two COVID-19 convalescents and expressed the antibody to test their neutralizing activity against diverse SARS-CoV-2 variants. Then, we resolved antibody-RBD complex structures of potent RBD-specific neutralizing antibodies by X-ray diffraction method. Finally, we analyzed the whole antibody repertoires of the two donors and studied the evolutionary pathway of potent neutralizing antibodies. Results and discussion: We identified three potent RBD-specific neutralizing antibodies (1D7, 3G10 and 3C11) from two COVID-19 convalescents that neutralized authentic SARS-CoV-2 WH-1 and Delta variant, and one of them, 1D7, presented broadly neutralizing activity against WH-1, Beta, Gamma, Delta and Omicron authentic viruses. The resolved antibody-RBD complex structures of two antibodies, 3G10 and 3C11, indicate that both of them interact with the external subdomain of the RBD and that they belong to the RBD-1 and RBD-4 communities, respectively. From the antibody repertoire analysis, we found that the CDR3 frequencies of the light chain, which shared high degrees of amino acid identity with these three antibodies, were higher than those of the heavy chain. This research will contribute to the development of RBD-specific antibody-based drugs and immunogens against multiple variants.

Circulating Plasma Concentrations of ACE2 in Primary Aldosteronism and Cardiovascular Outcomes.

CONTEXT: The plasma concentrations of angiotensin-converting enzyme 2 (pACE2) has been independently associated with cardiovascular diseases. OBJECTIVE: Higher pACE2 concentrations may be found in patients with primary aldosteronism (PA) and might lead to increased cardiovascular events. METHODS: Using an inception observational cohort, we examined pACE2 among 168 incident patients with PA. The expression of ACE2, serine protease 2 (TMPRSS2), and metalloprotease 17 (ADAM17) were assessed in peripheral blood mononuclear cells. RESULTS: Incident PA and essential hypertension (EH) patients had similarly elevated pACE2 (47.04 ± 22.06 vs 46.73 ± 21.06 ng/mL; P = .937). Age was negatively (ß = -2.15; P = .033) and higher serum potassium level (ß = 2.29; P = .024) was positively correlated with higher pACE2 in PA patients. Clinical complete hypertension remission after adrenalectomy (Primary Aldosteronism Surgery Outcome criteria) was achieved in 36 (50%) of 72 surgically treated unilateral PA (uPA) patients. At follow-up, pACE2 decreased in surgically treated patients who had (P < .001) or had no (P = .006) hypertension remission, but the pACE2 attenuation was not statistically significant in uPA (P = .085) and bilateral PA (P = .409) administered with mineralocorticoid receptor antagonist (MRA). Persistently elevated pACE2 (> 23 ng/mL) after targeted treatments was related to all-cause mortality and cardiovascular events among PA patients (hazard ratio = 8.8; P = .04); with a mean follow-up of 3.29 years. TMPRSS2 messenger RNA (mRNA) expression was higher in uPA (P = .018) and EH (P = .038) patients than in normotensive controls; it was also decreased after adrenalectomy (P < .001). CONCLUSION: PA and EH patients had elevated pACE2 and higher expression of TMPRSS2 mRNA compared to those of normotensive population. Persistently elevated pACE2 (> 23 ng/mL) after targeted treatments was associated risk of mortality and incident cardiovascular events.

Coronavirus Mask Protection Algorithm: A New Bio-inspired Optimization Algorithm and Its Applications.

Nowadays, meta-heuristic algorithms are attracting widespread interest in solving high-dimensional nonlinear optimization problems. In this paper, a COVID-19 prevention-inspired bionic optimization algorithm, named Coronavirus Mask Protection Algorithm (CMPA), is proposed based on the virus transmission of COVID-19. The main inspiration for the CMPA originated from human self-protection behavior against COVID-19. In CMPA, the process of infection and immunity consists of three phases, including the infection stage, diffusion stage, and immune stage. Notably, wearing masks correctly and safe social distancing are two essential factors for humans to protect themselves, which are similar to the exploration and exploitation in optimization algorithms. This study simulates the self-protection behavior mathematically and offers an optimization algorithm. The performance of the proposed CMPA is evaluated and compared to other state-of-the-art metaheuristic optimizers using benchmark functions, CEC2020 suite problems, and three truss design problems. The statistical results demonstrate that the CMPA is more competitive among these state-of-the-art algorithms. Further, the CMPA is performed to identify the parameters of the main girder of a gantry crane. Results show that the mass and deflection of the main girder can be improved by 16.44% and 7.49%, respectively.

Country Parks as Sites of Emergency Medical Facility: A Case of COVID-19 in Hangzhou, China.

City parks are suitable sites for the construction of emergency medical facilities. A comparison of various types of city parks revealed that country parks fit closely with site selection conditions for emergency medical facilities. Based on the latter site selection requirements, eight impact factors such as park type, effective avoidance area, spatial fragmentation degree, water source protection area, wind direction, distance from city center, impermeability, and transport duration were quantified, and then 29 country parks in the Hangzhou Urban Area were compared using Principal Component Analysis (PCA). The calculation results showed that Linglong Country Park has the highest score, taking into account the characteristics of safety, scalability, rehabilitation, convenience, pollution prevention, and isolation. Linglong can be given priority selection as a target location for emergency medical facilities. In addition, Silver Lake Country Park, Dongqiao Country Park, Taihuyuan Country Park, and Tuankou Country Park have higher scores and can be used as alternative targets for emergency plans. The scoring results prove that the evaluation method has a high degree of rigor, a significant degree of discrimination, and a high degree of consistency between the validity and weight assignment of each impact factor. In view of the different geographical conditions in each region, the weight assignment of each impact factor can be adjusted according to local conditions and can help make effective use of existing conditions and avoid disadvantages.

Understanding consumers' intention to use autonomous delivery vehicles during the COVID-19 pandemic: The stimulus-organism-response approach (preprint)

Autonomous delivery vehicles (ADVs) have attracted much attention since COVID-19. As an emerging last-mile delivery tool, the large-scale implementation of ADVs depends on consumers’ willingness to adopt them. However, until recently, research on user acceptance and adopting emerging technology has been relatively rare. The present study is the first that applies the stimulus-organism-response (S-O-R) model to investigate how stimulating factors (COVID-19 risk and human-computer interaction) affect consumers’ intention to use ADVs in last-mile delivery by triggering consumers’ inner states (delivery risk, price sensitivity, perceived enjoyment, trust in technology). Quantitative data based on university students in Zhejiang, China, was collected through an online survey platform (n = 298), and structural equation modeling was undertaken. The results reveal that COVID-19 risk and human-computer interaction can lead to adoption behaviors by triggering different inner states of consumers. Further, innovation is also considered to be one of the factors determining behavioral intention. The findings have profound theoretical and practical contributions to last-mile delivery and technology acceptance research.

Minimalist Nanocomplex with Dual Regulation of Endothelial Function and Inflammation for Targeted Therapy of Inflammatory Vascular Diseases.

Vascular disorders, characterized by vascular endothelial dysfunction combined with inflammation, are correlated with numerous fatal diseases, such as coronavirus disease-19 and atherosclerosis. Achieving vascular normalization is an urgent problem that must be solved when treating inflammatory vascular diseases. Inspired by the vascular regulatory versatility of nitric oxide (NO) produced by endothelial nitric oxide synthase (eNOS) catalyzing l-arginine (l-Arg), the eNOS-activating effects of l-Arg, and the powerful anti-inflammatory and eNOS-replenishing effects of budesonide (BUD), we constructed a bi-prodrug minimalist nanoplatform co-loaded with BUD and l-Arg via polysialic acid (PSA) to form BUD-l-Arg@PSA. This promoted vascular normalization by simultaneously regulating vascular endothelial dysfunction and inflammation. Mediated by the special affinity between PSA and E-selectin, which is highly expressed on the surface of activated endothelial cells (ECs), BUD-l-Arg@PSA selectively accumulated in activated ECs, targeted eNOS expression and activation, and promoted NO production. Consequently, the binary synergistic regulation of the NO/eNOS signaling pathway occurred and improved vascular endothelial function. NO-induced nuclear factor-kappa B alpha inhibitor (IκBα) stabilization and BUD-induced nuclear factor-kappa B (NF-κB) response gene site occupancy achieved dual-site blockade of the NF-κB signaling pathway, thereby reducing the inflammatory response and inhibiting the infiltration of inflammation-related immune cells. In a renal ischemia-reperfusion injury mouse model, BUD-l-Arg@PSA reduced acute injury. In an atherosclerosis mouse model, BUD-l-Arg@PSA decreased atherosclerotic plaque burden and improved vasodilation. This represents a revolutionary therapeutic strategy for inflammatory vascular diseases.

Immune response and homeostasis mechanism following administration of BBIBP-CorV SARS-CoV-2 inactivated vaccine.

The BBIBP-CorV severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) inactivated vaccine has been authorized for emergency use and widely distributed. We used single-cell transcriptome sequencing to characterize the dynamics of immune responses to the BBIBP-CorV inactivated vaccine. In addition to the expected induction of humoral immunity, we found that the inactivated vaccine induced multiple, comprehensive immune responses, including significantly increased proportions of CD16+ monocytes and activation of monocyte antigen presentation pathways; T cell activation pathway upregulation in CD8+ T cells, along with increased activation of CD4+ T cells; significant enhancement of cell-cell communications between innate and adaptive immunity; and the induction of regulatory CD4+ T cells and co-inhibitory interactions to maintain immune homeostasis after vaccination. Additionally, comparative analysis revealed higher neutralizing antibody levels, distinct expansion of naive T cells, a shared increased proportion of regulatory CD4+ T cells, and upregulated expression of functional genes in booster dose recipients with a longer interval after the second vaccination. Our research will support a comprehensive understanding of the systemic immune responses elicited by the BBIBP-CorV inactivated vaccine, which will facilitate the formulation of better vaccination strategies and the design of new vaccines.

Pre-existing anti-HCoV-OC43 immunity influences the durability and cross-reactivity of humoral response to SARS-CoV-2 vaccination.

Purpose: This study was conducted in order to properly understand whether prior seasonal human coronavirus (HCoV) immunity could impact the potential cross-reactivity of humoral responses induced by SARS-CoV-2 vaccine, thereby devising universal coronavirus vaccines for future outbreaks. Methods: We performed enzyme-linked immunosorbent assay (ELISA) to quantify the immunoglobulin G (IgG) antibody levels to spike (S) protein and S1 subunit of HCoVs (HCoV-OC43, HCoV-HKU1, HCoV-NL63, and HCoV-229E), and ELISA [anti-RBD and anti-nucleoprotein (N)], chemiluminescence immunoassay assays (anti-RBD), pseudovirus neutralization test, and authentic viral neutralization test to detect the binding and neutralizing antibodies to SARS-CoV-2 in the vaccinees. Results: We found that the antibody of seasonal HCoVs did exist before vaccination and could be boosted by SARS-CoV-2 vaccine. A further analysis demonstrated that the prior S and S1 IgG antibodies of HCoV-OC43 were positively correlated with anti-RBD and neutralization antibodies to SARS-CoV-2 at 12 and 24 weeks after the second vaccination, and the correlation is more statistically significant at 24 weeks. The persistent antibody levels of SARS-CoV-2 were observed in vaccinees with higher pre-existing HCoV-OC43 antibodies. Conclusion: Our data indicate that inactivated SARS-CoV-2 vaccination may confer cross-protection against seasonal coronaviruses in most individuals, and more importantly, the pre-existing HCoV-OC43 antibody was associated with protective immunity to SARS-CoV-2, supporting the development of a pan-coronavirus vaccine.

An imported case of ovale malaria in Xinjiang during the epidemic period of COVID-19

On December 13, 2020, Yutian County People's hospital reported one imported malaria case in Hotan, Xinjiang. The patient had worked and lived in Yaounde, Cameroon, from January to September 2020. He was infected with malaria twice in March and May 2020. Antimalarial treatment was administrated by the team doctor for 2-3 days in each treatment. The treatment was stopped after the symptoms improved. The patient returned to China on September 16 and was hospitalized on December 13 due to a high fever of 39 degrees C and upper respiratory symptoms. Multiple detections of COVID-19 nucleic acid showed negative results. Peripheral blood from the patient was taken for Plasmodium rapid diagnostic test (RDT), which showed a positive result suggesting non Plasmodium falciparum infection. Ring stage P. ovale was found in the blood smear. Nested PCR showed positive for P. ovale. A diagnosis of imported ovale malaria was made. The patient was administrated with 4 dihydroartemisinin piperaquine tablets and 3 primaquine phosphate tablets daily. The malaria parasite test became negative after 8 days of treatment. The patient was followed up for 3 months after discharge and had no symptoms of chills or fever.

Pre-existing anti-HCoV-OC43 immunity influences the durability and cross-reactivity of humoral response to SARS-CoV-2 vaccination

Purpose This study was conducted in order to properly understand whether prior seasonal human coronavirus (HCoV) immunity could impact the potential cross-reactivity of humoral responses induced by SARS-CoV-2 vaccine, thereby devising universal coronavirus vaccines for future outbreaks. Methods We performed enzyme-linked immunosorbent assay (ELISA) to quantify the immunoglobulin G (IgG) antibody levels to spike (S) protein and S1 subunit of HCoVs (HCoV-OC43, HCoV-HKU1, HCoV-NL63, and HCoV-229E), and ELISA [anti-RBD and anti-nucleoprotein (N)], chemiluminescence immunoassay assays (anti-RBD), pseudovirus neutralization test, and authentic viral neutralization test to detect the binding and neutralizing antibodies to SARS-CoV-2 in the vaccinees. Results We found that the antibody of seasonal HCoVs did exist before vaccination and could be boosted by SARS-CoV-2 vaccine. A further analysis demonstrated that the prior S and S1 IgG antibodies of HCoV-OC43 were positively correlated with anti-RBD and neutralization antibodies to SARS-CoV-2 at 12 and 24 weeks after the second vaccination, and the correlation is more statistically significant at 24 weeks. The persistent antibody levels of SARS-CoV-2 were observed in vaccinees with higher pre-existing HCoV-OC43 antibodies. Conclusion Our data indicate that inactivated SARS-CoV-2 vaccination may confer cross-protection against seasonal coronaviruses in most individuals, and more importantly, the pre-existing HCoV-OC43 antibody was associated with protective immunity to SARS-CoV-2, supporting the development of a pan-coronavirus vaccine.

In Silico Screening of Novel TMPRSS2 Inhibitors for Treatment of COVID-19.

COVID-19, a pandemic caused by the virus SARS-CoV-2, has spread globally, necessitating the search for antiviral compounds. Transmembrane protease serine 2 (TMPRSS2) is a cell surface protease that plays an essential role in SARS-CoV-2 infection. Therefore, researchers are searching for TMPRSS2 inhibitors that can be used for the treatment of COVID-19. As such, in this study, based on the crystal structure, we targeted the active site of TMPRSS2 for virtual screening of compounds in the FDA database. Then, we screened lumacaftor and ergotamine, which showed strong binding ability, using 100 ns molecular dynamics simulations to study the stability of the protein-ligand binding process, the flexibility of amino acid residues, and the formation of hydrogen bonds. Subsequently, we calculated the binding free energy of the protein-ligand complex by the MM-PBSA method. The results show that lumacaftor and ergotamine interact with residues around the TMPRSS2 active site, and reached equilibrium in the 100 ns molecular dynamics simulations. We think that lumacaftor and ergotamine, which we screened through in silico studies, can effectively inhibit the activity of TMPRSS2. Our findings provide a basis for subsequent in vitro experiments, having important implications for the development of effective anti-COVID-19 drugs.

Identification of T cell epitopes in BALB/c mice immunized with COVID-19 vaccine

Objective: To identify the T cell epitopes of the COVID-19 vaccine carrying SARS-CoV-2 S, N and M genes in BALB/c mice.

Polymersomes as virus-surrogate particles for evaluating the performance of air filter materials.

The development of antivirus air filter materials has attracted considerable interests due to the pandemic of coronavirus disease 2019 (COVID-19). Filtration efficiency (FE) of these materials against virus is critical in the assessment of their use in disease prevention. Due to the high cost and biosafety laboratory required for conducting research using actual virus samples, surrogates for virus are commonly used in the filtration test. Here, we explore the employment of polymersomes (polymeric vesicles) as a new type of surrogate. The polymersomes are hollow shell nanoparticles with amphiphilic bilayer membranes, which can be fabricated in nanosized, and possess similar size and structural features to virus. The performance of commercial KN95 mask and surgical mask with micro-sized fibers, and electrospun polyvinylidene fluoride (PVDF) and polyacrylonitrile (PAN) nanofibers were chosen to be evaluated. The filtration tests against fluorescent-labeled virus-surrogate particles (VSPs), i.e. polymersomes, allowed the determination of the FE of the multilayered filter materials in a layer-specific manner. The results suggested the importance of hydrophobicity in designing the nanofibrous filter materials. The employment of VSPs in filtration performance evaluation allows a cost-effective way to estimate the FE against virus, providing guidance on future development of air filter materials.

Occurrence and risk assessment of typical PPCPs and biodegradation pathway of ribavirin in wastewater treatment plants.

A large number of pharmaceuticals and personal care products (PPCPs) persist in wastewater, and the consumption of PPCPs for COVID-19 control and prevention has sharply increased during the pandemic. This study investigated the occurrence, removal efficiency, and risk assessment of six typical PPCPs commonly used in China in two wastewater treatment plants (WWTPs). Ribavirin (RBV) is an effective pharmaceutical for severely ill patients with COVID-19, and the possible biodegradation pathway of RBV by activated sludge was discovered. The experimental results showed that PPCPs were detected in two WWTPs with a detection rate of 100% and concentrations ranging between 612 and 2323 ng L-1. The detection frequency and concentrations of RBV were substantially higher, with a maximum concentration of 314 ng L-1. Relatively high pollution loads were found for the following PPCPs from influent: ibuprofen > ranitidine hydrochloride > RBV > ampicillin sodium > clozapine > sulfamethoxazole. The removal efficiency of PPCPs was closely related to adsorption and biodegradation in activated sludge, and the moving bed biofilm reactor (MBBR) had a higher removal capacity than the anoxic-anaerobic-anoxic-oxic (AAAO) process. The removal efficiencies of sulfamethoxazole, ampicillin sodium, ibuprofen, and clozapine ranged from 92.21% to 97.86% in MBBR process and were relatively low, from 61.82% to 97.62% in AAAO process, and the removal of RBV and ranitidine hydrochloride were lower than 42.96% in both MBBR and AAAO processes. The discrepancy in removal efficiency is caused by temperature, hydrophilicity, and hydrophobicity of the compound, and acidity and alkalinity. The transformation products of RBV in activated sludge were detected and identified, and the biodegradation process of RBV could be speculated as follows: first breaks into TCONH2 and an oxygen-containing five-membered heterocyclic ring under the nucleosidase reaction, and then TCONH2 is finally formed into TCOOH through amide hydrolysis. Aquatic ecological risks based on risk quotient (RQ) assessment showed that PPCPs had high and medium risks in the influent, and the RQ values were all reduced after MBBR and AAAO treatment. Ranitidine hydrochloride and clozapine still showed high and medium risks in the effluent, respectively, and thus presented potential risks to the aquatic ecosystem.

Epidemics, Convergence, and Common Prosperity: Evidence from China

This article investigates the impact of previous epidemics on rural development and convergence, and identifies the impact's mechanism based on convergence tests. Using a balanced panel of 31 provinces, the empirical results from 2002 to 2019 show that epidemics decelerated convergence in rural per capita income. The mechanism analysis shows that the accelerated divergence in wages and the decelerated convergence in business income were the major drivers, which also led to decelerated convergence in rural per capita consumption. Although epidemics have not threatened rural food consumption and the Engel coefficient of rural households, these two indicators of basic living needs have failed to achieve convergence across regions. The overall impact of an epidemic on convergence in rural–urban income disparity has also been insignificant, indicating that epidemics have affected rural and urban development simultaneously. Finally, COVID‐19 is likely to decelerate convergence in rural income, rural consumption, and urban income.

Testing Communication Concepts on COVID-19 Contact Tracing Among Black and Latinx/Hispanic People in the United States.

OBJECTIVE: Black and Latinx/Hispanic people were more than twice as likely to die from COVID-19 than White people, but because of legacies of discrimination and maltreatment in health care, were less likely to participate in some public health responses to COVID-19, including contact tracing. This study aimed to test three communication campaign concepts to engage Black and Latinx/Hispanic people in contact tracing efforts. METHODS: Twelve focus group discussions with 5 to 10 participants each were conducted online among participants from Black and Latinx/Hispanic urban populations in Philadelphia and New York state. Participants provided sociodemographic information and were presented with potential campaign concepts and prompted to rate the concepts and engage in open-ended discussion. For rating and sociodemographic data, chi-square tests were performed. For open-ended discussion data, a thematic analysis approach was used. RESULTS: Across groups, the campaign concept that was rated most likely to encourage cooperation with contact tracing efforts was "Be the One," with 45% of total first-place votes. Participants expressed that the campaign caught their attention (79%), motivated them to engage with contact tracers (71%) and to talk to others about contact tracing (77%). Discussions also elucidated: the importance of community engagement; the need for clearer explanations of contact tracing; the preference for already trusted, community-based contact tracers; the need to reassure people about confidentiality; and for contact tracing to be culturally competent and empathetic. CONCLUSIONS: This study highlights how strategic, culturally sensitive communication can buttress current and future contact tracing efforts, especially among Black and Latinx/Hispanic people.

Bayesian data assimilation for estimating instantaneous reproduction numbers during epidemics: Applications to COVID-19.

Estimating the changes of epidemiological parameters, such as instantaneous reproduction number, Rt, is important for understanding the transmission dynamics of infectious diseases. Current estimates of time-varying epidemiological parameters often face problems such as lagging observations, averaging inference, and improper quantification of uncertainties. To address these problems, we propose a Bayesian data assimilation framework for time-varying parameter estimation. Specifically, this framework is applied to estimate the instantaneous reproduction number Rt during emerging epidemics, resulting in the state-of-the-art 'DARt' system. With DARt, time misalignment caused by lagging observations is tackled by incorporating observation delays into the joint inference of infections and Rt; the drawback of averaging is overcome by instantaneously updating upon new observations and developing a model selection mechanism that captures abrupt changes; the uncertainty is quantified and reduced by employing Bayesian smoothing. We validate the performance of DARt and demonstrate its power in describing the transmission dynamics of COVID-19. The proposed approach provides a promising solution for making accurate and timely estimation for transmission dynamics based on reported data.