Cationic crosslinked carbon dots-adjuvanted intranasal vaccine induces protective immunity against Omicron-included SARS-CoV-2 variants.

Mucosal immunity plays a significant role in the first-line defense against viruses transmitted and infected through the respiratory system, such as SARS-CoV-2. However, the lack of effective and safe adjuvants currently limits the development of COVID-19 mucosal vaccines. In the current study, we prepare an intranasal vaccine containing cationic crosslinked carbon dots (CCD) and a SARS-CoV-2 antigen, RBD-HR with spontaneous antigen particlization. Intranasal immunization with CCD/RBD-HR induces high levels of antibodies with broad-spectrum neutralization against authentic viruses/pseudoviruses of Omicron-included variants and protects immunized female BALB/c mice from Omicron infection. Despite strong systemic cellular immune response stimulation, the intranasal CCD/RBD-HR vaccine also induces potent mucosal immunity as determined by the generation of tissue-resident T cells in the lungs and airway. Moreover, CCD/RBD-HR not only activates professional antigen-presenting cells (APCs), dendritic cells, but also effectively targets nasal epithelial cells, promotes antigen binding via sialic acid, and surprisingly provokes the antigen-presenting of nasal epithelial cells. We demonstrate that CCD is a promising intranasal vaccine adjuvant for provoking strong mucosal immunity and might be a candidate adjuvant for intranasal vaccine development for many types of infectious diseases, including COVID-19.

A novel heterologous receptor-binding domain dodecamer universal mRNA vaccine against SARS-CoV-2 variants.

There are currently approximately 4,000 mutations in the SARS-CoV-2 S protein gene and emerging SARS-CoV-2 variants continue to spread rapidly worldwide. Universal vaccines with high efficacy and safety urgently need to be developed to prevent SARS-CoV-2 variants pandemic. Here, we described a novel self-assembling universal mRNA vaccine containing a heterologous receptor-binding domain (HRBD)-based dodecamer (HRBDdodecamer) against SARS-CoV-2 variants, including Alpha (B.1.1.7), Beta (B.1.351), Gamma (B.1.1.28.1), Delta (B.1.617.2) and Omicron (B.1.1.529). HRBD containing four heterologous RBD (Delta, Beta, Gamma, and Wild-type) can form a stable dodecameric conformation under T4 trimerization tag (Flodon, FD). The HRBDdodecamer -encoding mRNA was then encapsulated into the newly-constructed LNPs consisting of a novel ionizable lipid (4N4T). The obtained universal mRNA vaccine (4N4T-HRBDdodecamer) presented higher efficiency in mRNA transfection and expression than the approved ALC-0315 LNPs, initiating potent immune protection against the immune escape of SARS-CoV-2 caused by evolutionary mutation. These findings demonstrated the first evidence that structure-based antigen design and mRNA delivery carrier optimization may facilitate the development of effective universal mRNA vaccines to tackle SARS-CoV-2 variants pandemic.

Manganese-coordinated mRNA vaccines with enhanced mRNA expression and immunogenicity induce robust immune responses against SARS-CoV-2 variants.

It is urgent to develop more effective mRNA vaccines against the emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants owing to the immune escape. Here, we constructed a novel mRNA delivery system [IC8/Mn lipid nanoparticles (IC8/Mn LNPs)]with high immunogenicity, via introducing a stimulator of interferon genes (STING) agonist [manganese (Mn)] based on a newly synthesized ionizable lipid (IC8). It was found that Mn can not only promote maturation of antigen-presenting cells via activating STING pathway but also improve mRNA expression by facilitating lysosomal escape for the first time. Subsequently, IC8/Mn LNPs loaded with mRNA encoding the Spike protein of SARS-CoV-2 Delta or Omicron variant (IC8/Mn@D or IC8/Mn@O) were prepared. Both mRNA vaccines induced substantial specific immunoglobulin G responses against Delta or Omicron. IC8/Mn@D displayed strong pseudovirus neutralization ability, T helper 1-biased immune responses, and good safety. It can be concluded that IC8/Mn LNPs have great potential for developing Mn-coordinated mRNA vaccines with robust immunogenicity and good safety.

A general equilibrium assessment of COVID-19's labor productivity impacts on china's regional economies.

This study introduces a database for analyzing COVID-19's impacts on China's regional economies. This database contains various sectoral and regional economic outcomes at the weekly and monthly level. In the context of a general equilibrium trade model, we first formulate a mathematical representation of the Chinese regional economy and calibrate the model with China's multi-regional input-output table. We then utilize the monthly provincial and sectoral value-added and national trade series to estimate COVID-19's province-by-month labor-productivity impacts from February 2020 to September 2020. As a year-on-year comparison, relative to February 2019 levels, we find an average 39.5% decrease in labor productivity (equivalent to around 305 million jobs) and an average 25.9% decrease in welfare. Labor productivity and welfare quickly returned to the recent high-growth trends for China in the latter half of 2020. By September 2020, relative to September 2019, average labor productivity increased by 12.2% (equivalent to around 94 million jobs) and average welfare increased by 8.2%.

A general equilibrium assessment of COVID-19's labor productivity impacts on china's regional economies

This study introduces a database for analyzing COVID-19’s impacts on China’s regional economies. This database contains various sectoral and regional economic outcomes at the weekly and monthly level. In the context of a general equilibrium trade model, we first formulate a mathematical representation of the Chinese regional economy and calibrate the model with China’s multi-regional input-output table. We then utilize the monthly provincial and sectoral value-added and national trade series to estimate COVID-19’s province-by-month labor-productivity impacts from February 2020 to September 2020. As a year-on-year comparison, relative to February 2019 levels, we find an average 39.5% decrease in labor productivity (equivalent to around 305 million jobs) and an average 25.9% decrease in welfare. Labor productivity and welfare quickly returned to the recent high-growth trends for China in the latter half of 2020. By September 2020, relative to September 2019, average labor productivity increased by 12.2% (equivalent to around 94 million jobs) and average welfare increased by 8.2%. Highlights We quantify COVID-19’s province-by-month labor productivity and welfare impacts on China’s economies. The analysis is based on a new database and a computable general equilibrium (CGE) modeling approach. Labor productivity declined by 39.5% in February 2020 but quickly recovered since April 2020. The recovery patterns are heterogeneous across regions.

COVID-19 induces new-onset insulin resistance and lipid metabolic dysregulation via regulation of secreted metabolic factors.

Abnormal glucose and lipid metabolism in COVID-19 patients were recently reported with unclear mechanism. In this study, we retrospectively investigated a cohort of COVID-19 patients without pre-existing metabolic-related diseases, and found new-onset insulin resistance, hyperglycemia, and decreased HDL-C in these patients. Mechanistically, SARS-CoV-2 infection increased the expression of RE1-silencing transcription factor (REST), which modulated the expression of secreted metabolic factors including myeloperoxidase, apelin, and myostatin at the transcriptional level, resulting in the perturbation of glucose and lipid metabolism. Furthermore, several lipids, including (±)5-HETE, (±)12-HETE, propionic acid, and isobutyric acid were identified as the potential biomarkers of COVID-19-induced metabolic dysregulation, especially in insulin resistance. Taken together, our study revealed insulin resistance as the direct cause of hyperglycemia upon COVID-19, and further illustrated the underlying mechanisms, providing potential therapeutic targets for COVID-19-induced metabolic complications.

Monetary incentives and peer referral in promoting secondary distribution of HIV self-testing among men who have sex with men in China: A randomized controlled trial.

BACKGROUND: Digital network-based methods may enhance peer distribution of HIV self-testing (HIVST) kits, but interventions that can optimize this approach are needed. We aimed to assess whether monetary incentives and peer referral could improve a secondary distribution program for HIVST among men who have sex with men (MSM) in China. METHODS AND FINDINGS: Between October 21, 2019 and September 14, 2020, a 3-arm randomized controlled, single-blinded trial was conducted online among 309 individuals (defined as index participants) who were assigned male at birth, aged 18 years or older, ever had male-to-male sex, willing to order HIVST kits online, and consented to take surveys online. We randomly assigned index participants into one of the 3 arms: (1) standard secondary distribution (control) group (n = 102); (2) secondary distribution with monetary incentives (SD-M) group (n = 103); and (3) secondary distribution with monetary incentives plus peer referral (SD-M-PR) group (n = 104). Index participants in 3 groups were encouraged to order HIVST kits online and distribute to members within their social networks. Members who received kits directly from index participants or through peer referral links from index MSM were defined as alters. Index participants in the 2 intervention groups could receive a fixed incentive ($3 USD) online for the verified test result uploaded to the digital platform by each unique alter. Index participants in the SD-M-PR group could additionally have a personalized peer referral link for alters to order kits online. Both index participants and alters needed to pay a refundable deposit ($15 USD) for ordering a kit. All index participants were assigned an online 3-month follow-up survey after ordering kits. The primary outcomes were the mean number of alters motivated by index participants in each arm and the mean number of newly tested alters motivated by index participants in each arm. These were assessed using zero-inflated negative binomial regression to determine the group differences in the mean number of alters and the mean number of newly tested alters motivated by index participants. Analyses were performed on an intention-to-treat basis. We also conducted an economic evaluation using microcosting from a health provider perspective with a 3-month time horizon. The mean number of unique tested alters motivated by index participants was 0.57 ± 0.96 (mean ± standard deviation [SD]) in the control group, compared with 0.98 ± 1.38 in the SD-M group (mean difference [MD] = 0.41),and 1.78 ± 2.05 in the SD-M-PR group (MD = 1.21). The mean number of newly tested alters motivated by index participants was 0.16 ± 0.39 (mean ± SD) in the control group, compared with 0.41 ± 0.73 in the SD-M group (MD = 0.25) and 0.57 ± 0.91 in the SD-M-PR group (MD = 0.41), respectively. Results indicated that index participants in intervention arms were more likely to motivate unique tested alters (control versus SD-M: incidence rate ratio [IRR = 2.98, 95% CI = 1.82 to 4.89, p-value < 0.001; control versus SD-M-PR: IRR = 3.26, 95% CI = 2.29 to 4.63, p-value < 0.001) and newly tested alters (control versus SD-M: IRR = 4.22, 95% CI = 1.93 to 9.23, p-value < 0.001; control versus SD-M-PR: IRR = 3.49, 95% CI = 1.92 to 6.37, p-value < 0.001) to conduct HIVST. The proportion of newly tested testers among alters was 28% in the control group, 42% in the SD-M group, and 32% in the SD-M-PR group. A total of 18 testers (3 index participants and 15 alters) tested as HIV positive, and the HIV reactive rates for alters were similar between the 3 groups. The total costs were $19,485.97 for 794 testers, including 450 index participants and 344 alter testers. Overall, the average cost per tester was $24.54, and the average cost per alter tester was $56.65. Monetary incentives alone (SD-M group) were more cost-effective than monetary incentives with peer referral (SD-M-PR group) on average in terms of alters tested and newly tested alters, despite SD-M-PR having larger effects. Compared to the control group, the cost for one more alter tester in the SD-M group was $14.90 and $16.61 in the SD-M-PR group. For newly tested alters, the cost of one more alter in the SD-M group was $24.65 and $49.07 in the SD-M-PR group. No study-related adverse events were reported during the study. Limitations include the digital network approach might neglect individuals who lack internet access. CONCLUSIONS: Monetary incentives alone and the combined intervention of monetary incentives and peer referral can promote the secondary distribution of HIVST among MSM. Monetary incentives can also expand HIV testing by encouraging first-time testing through secondary distribution by MSM. This social network-based digital approach can be expanded to other public health research, especially in the era of the Coronavirus Disease 2019 (COVID-19). TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR) ChiCTR1900025433.

Imatinib and methazolamide ameliorate COVID-19-induced metabolic complications via elevating ACE2 enzymatic activity and inhibiting viral entry.

Coronavirus disease 2019 (COVID-19) represents a systemic disease that may cause severe metabolic complications in multiple tissues including liver, kidney, and cardiovascular system. However, the underlying mechanisms and optimal treatment remain elusive. Our study shows that impairment of ACE2 pathway is a key factor linking virus infection to its secondary metabolic sequelae. By using structure-based high-throughput virtual screening and connectivity map database, followed with experimental validations, we identify imatinib, methazolamide, and harpagoside as direct enzymatic activators of ACE2. Imatinib and methazolamide remarkably improve metabolic perturbations in vivo in an ACE2-dependent manner under the insulin-resistant state and SARS-CoV-2-infected state. Moreover, viral entry is directly inhibited by these three compounds due to allosteric inhibition of ACE2 binding to spike protein on SARS-CoV-2. Taken together, our study shows that enzymatic activation of ACE2 via imatinib, methazolamide, or harpagoside may be a conceptually new strategy to treat metabolic sequelae of COVID-19.

[Variation Characteristics of Ambient Volatile Organic Compounds (VOCs) Volume Fraction During Hangzhou COVID-19 Period].

A continuous observation campaign was carried out with the Syntech Spectras GC955 volatile organics online monitoring system from December 1, 2019 to March 31, 2020 during the COVID-19 period in Hangzhou. Composition characteristics, diurnal variation, and atmospheric chemical reactivity of VOCs were analyzed. The results showed that φ(total VOCs) were the highest before the COVID-19 pandemic in different sites and the lowest during the first response period. The φ(total VOCs) at night was higher than that during the day. The daily variation in Wolongqiao φ(total VOCs) was less than that in Xiasha. The daily variation in φ(total VOCs) during the first level response period was less than that during the other three periods. The diurnal variation in the φ (total VOCs) in Xiasha showed a "V" shape, and that in Wolongqiao showed a typical bimodal structure. The OFP in Xiasha was higher than that in Wolongqiao. The OFP were the highest at the two sites before the COVID-19 pandemic. The OFP was the lowest during the first response period in Xiasha and the lowest during the second response period in Wolongqiao. The OFP of aromatics and olefins was higher, and the OFP of alkynes was the lowest in Xiasha. The OFP of olefin in Wolongqiao was much higher than that of the other three components, followed by alkane and alkyne.

The impact of COVID-19 on seasoned equity offering: Evidence from China

Abstract This study examines the impact from the COVID-19 pandemic on the association between Chinese firms' SEO announcements and market reaction afterwards. Our findings indicate that market investors would respond more negatively to the SEO announcements and undergo more SEO underpricing for firms from regions significantly affected by the pandemic than those from the less-affected regions. Furthermore, higher CSR scores and more involvements in accounting conservatism could mitigate these effects. The main mechanism of the moderating effect from CSR performance and accounting conservatism is that CSR investment and accounting conservatism could lessen information asymmetry between the SEO announced firms and outside investors. Finally, we document that the main motivation of SEO issuance during the pandemic is market timing.

Author Correction: Temporal dynamics in viral shedding and transmissibility of COVID-19.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Maternal, placental and neonatal outcomes after asymptomatic SARS-CoV-2 infection in the first trimester of pregnancy: A case report.

The effects of SARS-CoV-2 infection in the first trimester on the pregnant woman and the fetus remain unclear. We describe the complete follow-up of a pregnant woman with asymptomatic SARS-CoV-2 infection in the first trimester. The woman tested positive for SARS-CoV-2 viral RNA in nasopharyngeal swabs in her seventh week of gestation and was admitted to a local hospital for treatment. Although the woman had a BMI above 28 and a total gestational weight gain of 21 kg, no pregnancy complications or severe complications related to SARS-CoV-2 were reported. An ultrasound scan identified no fetal abnormalities at 22 weeks. The pregnancy ended at term (37 weeks), and the newborn's birth weight was 3100 g. Placental insufficiency was revealed by placental histology examination but this appeared not to be related to the SARS-CoV-2 infection. In-situ hybridisation and immunohistochemical tests for SARS-CoV-2 RNA, spike protein 1, and nucleocapsid proteins were negative. However, ACE-2 was positive in samples of the placenta, umbilical cord and fetal membrane. The baby was followed up through to 10 days after birth and grew normally. Our results suggest that asymptomatic SARS-CoV-2 infection in the first trimester of pregnancy might not have significant harmful effects on the mother and the developing fetus. This finding may be of interest to the general public, midwives and general practitioners. However, large population studies are needed to confirm our findings.

Generation of SARS-CoV-2 reporter replicon for high-throughput antiviral screening and testing.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) research and antiviral discovery are hampered by the lack of a cell-based virus replication system that can be readily adopted without biosafety level 3 (BSL-3) restrictions. Here, the construction of a noninfectious SARS-CoV-2 reporter replicon and its application in deciphering viral replication mechanisms and evaluating SARS-CoV-2 inhibitors are presented. The replicon genome is replication competent but does not produce progeny virions. Its replication can be inhibited by RdRp mutations or by known SARS-CoV-2 antiviral compounds. Using this system, a high-throughput antiviral assay has also been developed. Significant differences in potencies of several SARS-CoV-2 inhibitors in different cell lines were observed, which highlight the challenges of discovering antivirals capable of inhibiting viral replication in vivo and the importance of testing compounds in multiple cell culture models. The generation of a SARS-CoV-2 replicon provides a powerful platform to expand the global research effort to combat COVID-19.

Longitudinal clinical and radiographic evaluation reveals interleukin-6 as an indicator of persistent pulmonary injury in COVID-19.

Rationale: Previous studies of coronavirus disease 2019 (COVID-19) were mainly focused on cross-sectional analysis. In this study, we sought to evaluate the dynamic changes of immunological and radiographic features, and the association with the outcome of pulmonary lesions in COVID-19 patients. Methods: Peripheral blood samples and radiographic data were collected longitudinally for up to 8 weeks from 158 laboratory-confirmed COVID-19 patients. The chest computed tomography (CT) scans were scored based on a semi-quantification assessment according to the extent of pulmonary abnormalities; the temporal change of the immunological and radiographic features was analyzed. Results: Compared with mild and moderate patients, severe patients had significantly decreased counts of lymphocytes, CD4+ T cells, CD8+ T cells, and CD19+ B cells but dramatically elevated counts of neutrophils and levels of interleukin (IL)-6. Sequential monitoring showed a sustained increase in lymphocytes counts and significantly decreased levels of IL-6 in severe patients during the disease course. Notably, patients with persistent pulmonary lesions (CT score ≥ 5 in week 8) showed high levels of IL-6 during the follow-up period, compared with those with recovery lesions (CT score < 5 in week 8). More importantly, the peak expression of IL-6 prior to the aggravated lung injury was mainly found in patients with persistent lesions, and multivariate analysis showed that IL-6 level upon admission was an independent factor associated with the persistent pulmonary injury. Conclusion: Prolonged elevation of IL-6 is associated with persistent pulmonary lesions in COVID-19 patients. Sequential monitoring and timely intervention of IL-6 may favor the clinical management of COVID-19.

Associations of clinical characteristics and treatment regimens with the duration of viral RNA shedding in patients with COVID-19.

OBJECTIVE: The novel coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a global pandemic, but the factors influencing viral RNA shedding, which would help inform optimal control strategies, remain unclear. METHODS: The clinical course and viral RNA shedding pattern of 267 consecutive symptomatic COVID-19 patients admitted to the hospital from January 20, 2020 to March 15, 2020 were evaluated retrospectively. RESULTS: The median duration of viral RNA shedding was 12 days (interquartile range 8-16 days) after the onset of illness. Of the 267 patients included in this study, 65.2% had viral RNA clearance within 14 days, 88.8% within 21 days, and 94.4% within 28 days. Older age (hazard ratio (HR) 0.99, 95% confidence interval (CI) 0.98-1.00; p = 0.04), time lag from illness onset to hospital admission (HR 0.91, 95% CI 0.88-0.94; p < 0.001), diarrhea (HR 0.59, 95% CI 0.36-0.96; p = 0.036), corticosteroid treatment (HR 0.60, 95% CI 0.39-0.94; p = 0.024), and lopinavir/ritonavir use (HR 0.70, 95% CI 0.52-0.94; p = 0.014) were significantly and independently associated with prolonged viral RNA shedding. CONCLUSIONS: Early detection and timely hospital admission may be warranted for symptomatic COVID-19 patients, especially for older patients and patients with diarrhea. Corticosteroid treatment is associated with prolonged viral RNA shedding and should be used with caution. Lopinavir/ritonavir use may be associated with prolonged viral RNA shedding in non-severe patients; further randomized controlled trials are needed to confirm this finding.

[Clinical characteristics and CT imaging features of patients with different clinical types of coronavirus disease 2019].

OBJECTIVE: To investigate the clinical characteristics and CT imaging features of patients with different clinical types of coronavirus disease 2019 (COVID-19), so as to provide a reference for the treatment and evaluation of COVID-19. METHODS: The clinical data of 278 patients with COVID-19 admitted to Guangzhou Eighth People's Hospital from January 20th to February 10th in 2020 were collected. The patients were divided into mild, ordinary, severe and critical types. The differences of clinical symptoms and signs, laboratory examination indexes and CT image features of lung in different clinical types were analyzed and compared, and the relationship between clinical and imaging features and clinical types of diseases were analyzed. RESULTS: Among the 278 patients with COVID-19, 130 were male (46.8%) and 148 were female (53.2%), of whom 88.8% (247/278) were 20 to 69 years old. 238 (85.6%) patients combined one or more basic diseases. The source of cases was mainly imported cases (n = 201, 72.3%), of whom 89 cases were imported from Wuhan, accounting for 44.3% of all imported cases. With the aggravation of the disease, the male composition ratio, age and the number of basic diseases of patients gradually increased, and the incidences of fever, dry cough, chilly or chills, and fatigue in severe and critical patients were significantly higher than those in the mild and ordinary ones. The white blood cell count (WBC), neutrophil counts (NEU) and proportions (NEU%) of the severe and critical patients were higher than those of the mild and ordinary patients [WBC (×109/L): 5.7±3.1, 6.5±2.4 vs. 5.4±1.7, 4.9±1.6; NEU (×109/L): 4.4±3.1, 4.9±2.5 vs. 2.8±1.2, 2.9±1.3; NEU%: 0.72±0.13, 0.73±0.14 vs. 0.51±0.12, 0.59±0.11; all P < 0.01], while the lymphocyte count (LYM) and ratio (LYM%), platelet count (PLT) were lower than those in the mild and ordinary patients [LYM (×109/L): 1.0±0.4, 1.2±0.8 vs. 2.1±0.9, 1.5±0.6; LYM%: 0.21±0.11, 0.20±0.12 vs. 0.40±0.11, 0.32±0.11; PLT (×109/L): 177.1±47.8, 157.7±51.6 vs. 215.3±59.7, 191.8±64.3; all P < 0.05]. The level of albumin (Alb) was the lowest in the critical patients and the level of total bilirubin (TBil) was the highest, which was statistically significant as compared with the mild, ordinary and severe patients [Alb (g/L): 33.0±5.8 vs. 42.8±4.4, 39.6±5.1, 34.4±4.2; TBil (µmol/L): 20.1±12.8 vs. 12.0±8.7, 10.9±6.3, 12.2±8.3; both P < 0.01]. Lactate dehydration (LDH) and cardiac troponin I (cTnI) in the severe and critical patients were significantly higher than those in the mild and ordinary patients [LDH (µmol×s-1×L-1): 5.6±2.2, 5.0±2.9 vs. 2.8±0.9, 3.3±1.2; cTnI (µg/L): 0.010 (0.006, 0.012), 0.010 (0.006, 0.012) vs. 0.005 (0.003, 0.006), 0.005 (0.001, 0.008); both P < 0.05]. C-reactive protein (CRP) level of severe patients were higher than that in the mild, ordinary and critical patients [mg/L: 43.3 (33.2, 72.1) vs. 22.1 (16.2, 25.7), 29.7 (19.8, 43.1), 25.8 (23.0, 36.7), P < 0.01]. The level of procalcitonin (PCT) in the severe and critical patients was higher than that in the mild and ordinary patients [µg/L: 0.17 (0.12, 0.26), 0.13 (0.09, 0.24) vs. 0.06 (0.05, 0.08), 0.05 (0.04, 0.09), P < 0.01]. The typical CT imaging features were as follows: the ordinary type mainly showed the single or multiple ground glass shadows on the chest image; the severe type mainly showed the multiple ground glass shadows, infiltration shadows or solid transformation shadows. Compared with the ordinary patients, the lesions increase, and the scope of the lesion expanded to show double lungs. Critical type was mainly manifested as diffuse consolidation of both lungs with multiple patchy density increase shadows, multiple leafy patchy density increase shadows were seen on each leaf, most of them were ground glass-like density, and some were shown separately lung consolidation. CONCLUSIONS: Men, advanced aged, and combining multiple underlying diseases are high-risk populations of COVID-19, and they should pay close attention to the risk of progressing to severe or critical type. CT imaging features could be used as an important supplement when diagnosing severe and critical COVID-19.

Monetary incentives and peer referral in promoting digital network-based secondary distribution of HIV self-testing among men who have sex with men in China: study protocol for a three-arm randomized controlled trial.

BACKGROUND: Human immunodeficiency virus (HIV) testing is a crucial strategy for HIV prevention. HIV testing rates remain low among men who have sex with men (MSM) in China. Digital network-based secondary distribution is considered as an effective model to enhance HIV self-testing (HIVST) among key populations. Digital platforms provide opportunities for testers to apply for HIVST kits by themselves, and secondary distribution allows them to apply for multiple kits to deliver to their sexual partners or members within their social network. We describe a three-arm randomized controlled trial to examine the effect of monetary incentives and peer referral in promoting digital network-based secondary distribution of HIVST among MSM in China. METHODS: Three hundred MSM in China will be enrolled through a digital platform for data collection. The eligibility criteria include being biological male, 18 years of age or over, ever having had sex with another man, being able to apply for kits via the online platform, and being willing to provide personal telephone number for follow-up. Eligible participants will be randomly allocated into one of the three arms: standard secondary distribution arm, secondary distribution with monetary incentives arm, and secondary distribution with monetary incentives plus peer referral arm. Participants (defined as "index") will distribute actual HIV self-test kits to members within their social network (defined as "alter") or share referral links to encourage alters to apply HIV self-test kits by themselves. All index participants will be requested to complete a baseline survey and a 3-month follow-up survey. Both indexes and alters will complete a survey upon returning the results by taking a photo of the used kits with the unique identification number. DISCUSSION: HIV testing rates remain suboptimal among MSM in China. Innovative interventions are needed to further expand the uptake of HIV testing among key populations. The findings of the trial can provide scientific evidence and experience on promoting secondary distribution of HIVST to reach key populations who have not yet been covered by existing testing services. TRIAL REGISTRATION: The study was registered in the Chinese Clinical Trial Registry (ChiCTR1900025433) on 26, August 2019, http://www.chictr.org.cn/showproj.aspx?proj=42001. Prospectively registered.

Temporal dynamics in viral shedding and transmissibility of COVID-19.

We report temporal patterns of viral shedding in 94 patients with laboratory-confirmed COVID-19 and modeled COVID-19 infectiousness profiles from a separate sample of 77 infector-infectee transmission pairs. We observed the highest viral load in throat swabs at the time of symptom onset, and inferred that infectiousness peaked on or before symptom onset. We estimated that 44% (95% confidence interval, 25-69%) of secondary cases were infected during the index cases' presymptomatic stage, in settings with substantial household clustering, active case finding and quarantine outside the home. Disease control measures should be adjusted to account for probable substantial presymptomatic transmission.

Management of COVID-19 in patients after liver transplantation: Beijing working party for liver transplantation.

Annually, around 850 liver transplantation is performed in Beijing, China. Recently, the new coronavirus pneumonia (COVID-19) caused by 2019 novel coronavirus (2019-nCoV) has affected nearly 200 countries worldwide. 2019-nCov can cause severe lung disease, multiple-organ damage, and significant mortalities. Liver transplant recipients, because of long-term oral immunosuppressant effects, may be more susceptible to 2019-nCoV infection and have a worse prognosis than the general population. It is urgent to set up guidelines for the prevention, diagnosis, and treatment of COVID-19 in liver transplant recipients. In this article, we reviewed the clinical aspects of 2019-nCoV infection, characteristics of liver transplant recipients, immunosuppressant usage, and potential drug interactions to provide recommendations to clinical staff managing liver transplant recipients during the COVID-19 epidemic.