Development of highly potent non-covalent inhibitors of SARS-CoV-2 3CLpro (preprint)

The SARS-CoV-2 virus is the causal agent of the ongoing pandemic of coronavirus disease 2019 (COVID-19). There is an urgent need for potent, specific antiviral compounds against SARS-CoV-2. The 3C-like protease (3CLpro) is an essential enzyme for the replication of SARS-CoV-2 and other coronaviruses, and thus is a target for coronavirus drug discovery. Nearly all inhibitors of coronavirus 3CLpro reported so far are covalent inhibitors. Here, we report the development of specific, non-covalent inhibitors of 3CLpro. The most potent one, WU-04, effectively blocks SARS-CoV-2 replications in human cells with EC 50 values in the 10-nM range. WU-04 also inhibits the 3CLpro of SARS-CoV and MERS-CoV with high potency, indicating that it is a pan-inhibitor of coronavirus 3CLpro. WU-04 showed anti-SARS-CoV-2 activity similar to that of PF-07321332 (Nirmatrelvir) in K18-hACE2 mice when the same dose was administered orally. Thus, WU-04 is a promising drug candidate for coronavirus treatment. One-Sentence Summary A oral non-covalent inhibitor of 3C-like protease effectively inhibits SARS-CoV-2 replication.

An Assessment of Poverty Alleviation Measures and Sustainable Livelihood Capability of Farm Households in Rural China: A Sustainable Livelihood Approach

This paper aims to identify effective mechanisms for government poverty alleviation measures based on the livelihood sustainability of farm households in Southern Shaanxi province, China. The paper utilizes data from 414 farm households, collected through field observations and in-depth interviews in 24 rural communes in Qinba Mountain Area of Shaanxi province, China. Using theoretical research methods and employing the sustainable livelihood approach (SLA) framework, this paper analyzes poverty alleviation measures as well as the impact of varied capital availability on sustainable livelihood. The study shows that developing local industries and governmental financial support improve the sustainable livelihood of farmers and eradicate absolute poverty. The findings of this study further indicate that there is a positive correlation between poverty alleviation measures and natural and social capital for sustainable livelihood. The paper provides empirical and quantitative evidence on alleviation of poverty, and the findings will help improve the sustainability of livelihood capability of farming households. This study suggests impactful approaches to stabilizing mechanisms for poverty alleviation in rural areas over the longer term.

Comparative effectiveness and safety of 32 pharmacological interventions recommended by guidelines for coronavirus disease 2019: a systematic review and network meta-analysis combining 66 trials.

BACKGROUND: The global pandemic coronavirus disease 2019 (COVID-19) has become a major public health problem and presents an unprecedented challenge. However, no specific drugs were currently proven. This study aimed to evaluate the comparative efficacy and safety of pharmacological interventions in patients with COVID-19. METHODS: Medline, Embase, the Cochrane Library, and clinicaltrials.gov were searched for randomized controlled trials (RCTs) in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)/SARS-CoV. Random-effects network meta-analysis within the Bayesian framework was performed, followed by the Grading of Recommendations Assessment, Development, and Evaluation system assessing the quality of evidence. The primary outcome of interest includes mortality, cure, viral negative conversion, and overall adverse events (OAEs). Odds ratio (OR) with 95% confidence interval (CI) was calculated as the measure of effect size. RESULTS: Sixty-six RCTs with 19,095 patients were included, involving standard of care (SOC), eight different antiviral agents, six different antibiotics, high and low dose chloroquine (CQ_HD, CQ_LD), traditional Chinese medicine (TCM), corticosteroids (COR), and other treatments. Compared with SOC, a significant reduction of mortality was observed for TCM (OR = 0.34, 95% CI: 0.20-0.56, moderate quality) and COR (OR = 0.84, 95% CI: 0.75-0.96, low quality) with improved cure rate (OR = 2.16, 95% CI: 1.60-2.91, low quality for TCM; OR = 1.17, 95% CI: 1.05-1.30, low quality for COR). However, an increased risk of mortality was found for CQ_HD vs. SOC (OR = 3.20, 95% CI: 1.18-8.73, low quality). TCM was associated with decreased risk of OAE (OR = 0.52, 95% CI: 0.38-0.70, very low quality) but CQ_HD (OR = 2.51, 95% CI: 1.20-5.24) and interferons (IFN) (OR = 2.69, 95% CI: 1.02-7.08) vs. SOC with very low quality were associated with an increased risk. CONCLUSIONS: COR and TCM may reduce mortality and increase cure rate with no increased risk of OAEs compared with standard care. CQ_HD might increase the risk of mortality. CQ, IFN, and other antiviral agents could increase the risk of OAEs. The current evidence is generally uncertain with low-quality and further high-quality trials are needed.

Reinfection could not occur in SARS-CoV-2 infected rhesus macaques (preprint)

A global pandemic of Corona Virus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome CoV-2 (SARS-CoV-2) is ongoing spread. It remains unclear whether the convalescing patients have a risk of reinfection. Rhesus macaques were rechallenged with SARS-CoV-2 during an early recovery phase from initial infection characterized by weight loss, interstitial pneumonia and systemic viral dissemination mainly in respiratory and gastrointestinal tracts. The monkeys rechallenged with the identical SARS-CoV-2 strain have failed to produce detectable viral dissemination, clinical manifestations and histopathological changes. A notably enhanced neutralizing antibody response might contribute the protection of rhesus macaques from the reinfection by SARS-CoV-2. Our results indicated that primary SARS-CoV-2 infection protects from subsequent reinfection. One Sentence SummaryNeutralizing antibodies against SARS-CoV-2 might protect rhesus macaques which have undergone an initial infection from reinfection during early recovery days.

Rhesus macaques can be effectively infected with SARS-CoV-2 via ocular conjunctival route (preprint)

The outbreak of Corona Virus Disease 2019 caused by the severe acute respiratory syndrome coronavirus (SARS-CoV-2) is highly transmitted. The potential extra-respiratory transmission routes remain uncertain. Five rhesus macaques were inoculated with 1x106 TCID50 of SARS-CoV-2 via conjunctival (CJ), intratracheal (IT), and intragastric (IG) routes, respectively. Remarkably, the CJ inoculated-macaques developed mild interstitial pneumonia and viral load was detectable in the conjunctival swabs at 1 days post-inoculation (dpi). Only via IT inoculation, viral load was detected in the anal swab at 1-7 dpi and macaque showed weight loss. However, viral load was undetectable after IG inoculation. Comparatively, viral load was higher in the nasolacrimal system but lesions of lung were relatively mild and local via CJ inoculation compared with that via IT inoculation, demonstrating distinct characteristics of virus dispersion. Both the two routes affected the alimentary tract. Therefore the clinicians need to protect eye while working with patients.

The Pathogenicity of 2019 Novel Coronavirus in hACE2 Transgenic Mice (preprint)

Severe acute respiratory syndrome CoV-2 (SARS-CoV-2) caused the Corona Virus Disease 2019 (COVID-19) cases in China has become a public health emergency of international concern (PHEIC). Based on angiotensin converting enzyme 2 (ACE2) as cell entry receptor of SARS-CoV, we used the hACE2 transgenic mice infected with SARS-CoV-2 to study the pathogenicity of the virus. Weight loss and virus replication in lung were observed in hACE2 mice infected with SARS-CoV-2. The typical histopathology was interstitial pneumonia with infiltration of significant lymphocytes and monocytes in alveolar interstitium, and accumulation of macrophages in alveolar cavities. Viral antigens were observed in the bronchial epithelial cells, alveolar macrophages and alveolar epithelia. The phenomenon was not found in wild type mice with SARS-CoV-2 infection. The pathogenicity of SARS-CoV-2 in hACE2 mice was clarified and the Kochs postulates were fulfilled as well, and the mouse model may facilitate the development of therapeutics and vaccines against SARS-CoV-2.