Identification and quantitative analysis of bioactive components from Potentilla kleiniana Wight et Arn with anti HIV-1 proteases activity.

Potentilla kleiniana Wight et Arn（PK, 'Wu Pi Feng' in Chinese） was recorded as Miao ethnic medicine for treatment of fever, cough, ulcer, and erysipelas for thousands years. This study aimed to evaluate the antiviral activity of four PK extracts and seven compounds by using HIV-1 protease (HIV-1 PR). In addition, Ultra-High Performance Liquid Chromatography and High Resolution Mass Spectrometry (UPLC-HRMS) was employed to identify the bioactive components. The toxicity assessment of the extracts was done before antiviral screening using a highly specific human aspartyl protease, renin protease by fluorimetric method. As a result, seven compounds and four extracts of PK inhibited HIV-1 PR with IC50 range from 0.009 to 0.36 mg/mL, and did not appreciably inhibit the general human protease renin. This study first demonstrated that four PK extracts, ellagic acid and ursolic acid potent inhibit HIV-1 protease, could be used as an efficacious drug candidate to treat SARS-CoV-2 infection.

Development of a Mobile Health Application Based on a Mixed Prenatal Care in the Context of COVID-19 Pandemic.

OBJECTIVE: We describe the development and structure of a novel mobile application in a mixed model of prenatal care, in the context of the COVID-19 pandemic. Furthermore, we assess the acceptability of this mobile app in a cohort of patients. METHODS: First, we introduced a mixed model of prenatal care; second, we developed a comprehensive, computer-based clinical record to support our system. Lastly, we built a novel mobile app as a tool for prenatal care. We used Flutter Software version 2.2 to build the app for Android and iOS smartphones. A cross-sectional study was carried out to assess the acceptability of the app. RESULTS: A mobile app was also built with the main attribute of being connected in real-time with the computer-based clinical records. The app screens detail information about activities programmed and developed in the prenatal care according to gestational age. A downloadable maternity book is available and some screens show warning signs and symptoms of pregnancy. The acceptability assessment was mostly rated positively regarding the characteristics of the mobile app, by 50 patients. CONCLUSION: This novel mobile app was developed as a tool among pregnant patients to increase the information available about their pregnancies in the provision of a mixed model of prenatal care in the context of the COVID-19 pandemic. It was fully customized to the needs of our users following the local protocols. The introduction of this novel mobile app was highly accepted by the patients.

Antifungal Activity and Potential Action Mechanism of Allicin against Trichosporon asahii.

Trichosporon asahii is an emerging opportunistic pathogen that causes potentially fatal disseminated trichosporonosis. The global prevalence of coronavirus disease 2019 (COVID-19) poses an increasing fungal infection burden caused by T. asahii. Allicin is the main biologically active component with broad-spectrum antimicrobial activity in garlic. In this study, we performed an in-depth analysis of the antifungal characteristics of allicin against T. asahii based on physiological, cytological, and transcriptomic assessments. In vitro, allicin inhibited the growth of T. asahii planktonic cells and biofilm cells significantly. In vivo, allicin improved the mean survival time of mice with systemic trichosporonosis and reduced tissue fungal burden. Electron microscopy observations clearly demonstrated damage to T. asahii cell morphology and ultrastructure caused by allicin. Furthermore, allicin increased intracellular reactive oxygen species (ROS) accumulation, leading to oxidative stress damage in T. asahii cells. Transcriptome analysis showed that allicin treatment disturbed the biosynthesis of cell membrane and cell wall, glucose catabolism, and oxidative stress. The overexpression of multiple antioxidant enzymes and transporters may also place an additional burden on cells, causing them to collapse. Our findings shed new light on the potential of allicin as an alternative treatment strategy for trichosporonosis. IMPORTANCE Systemic infection caused by T. asahii has recently been recognized as an important cause of mortality in hospitalized COVID-19 patients. Invasive trichosporonosis remains a significant challenge for clinicians, due to the limited therapeutic options. The present work suggests that allicin holds great potential as a therapeutic candidate for T. asahii infection. Allicin demonstrated potent in vitro antifungal activity and potential in vivo protective effects. In addition, transcriptome sequencing provided valuable insights into the antifungal effects of allicin.

Studying pulmonary fibrosis due to microbial infection via automated microscopic image analysis.

Introduction: Pulmonary fibrosis is a consequential complication of microbial infections, which has notably been observed in SARS-CoV-2 infections in recent times. Macrophage polarization, specifically the M2-type, is a significant mechanism that induces pulmonary fibrosis, and its role in the development of Post- COVID-19 Pulmonary Fibrosis is worth investigating. While pathological examination is the gold standard for studying pulmonary fibrosis, manual review is subject to limitations. In light of this, we have constructed a novel method that utilizes artificial intelligence techniques to analyze fibro-pathological images. This method involves image registration, cropping, fibrosis degree classification, cell counting and calibration, and it has been utilized to analyze microscopic images of COVID-19 lung tissue. Methods: Our approach combines the Transformer network with ResNet for fibrosis degree classification, leading to a significant improvement over the use of ResNet or Transformer individually. Furthermore, we employ semi-supervised learning which utilize both labeled and unlabeled data to enhance the ability of the classification network in analyzing complex samples. To facilitate cell counting, we applied the Trimap method to localize target cells. To further improve the accuracy of the counting results, we utilized an effective area calibration method that better reflects the positive density of target cells. Results: The image analysis method developed in this paper allows for standardization, precision, and staging of pulmonary fibrosis. Analysis of microscopic images of COVID-19 lung tissue revealed a significant number of macrophage aggregates, among which the number of M2-type macrophages was proportional to the degree of fibrosis. Discussion: The image analysis method provids a more standardized approach and more accurate data for correlation studies on the degree of pulmonary fibrosis. This advancement can assist in the treatment and prevention of pulmonary fibrosis. And M2-type macrophage polarization is a critical mechanism that affects pulmonary fibrosis, and its specific molecular mechanism warrants further exploration.

Transcription factor Dmrt1 triggers the SPRY1-NF-κB pathway to maintain testicular immune homeostasis and male fertility.

Bacterial or viral infections, such as Brucella, mumps virus, herpes simplex virus, and Zika virus, destroy immune homeostasis of the testes, leading to spermatogenesis disorder and infertility. Of note, recent research shows that SARS-CoV-2 can infect male gonads and destroy Sertoli and Leydig cells, leading to male reproductive dysfunction. Due to the many side effects associated with antibiotic therapy, finding alternative treatments for inflammatory injury remains critical. Here, we found that Dmrt1 plays an important role in regulating testicular immune homeostasis. Knockdown of Dmrt1 in male mice inhibited spermatogenesis with a broad inflammatory response in seminiferous tubules and led to the loss of spermatogenic epithelial cells. Chromatin immunoprecipitation sequencing (ChIP-seq) and RNA sequencing (RNA-seq) revealed that Dmrt1 positively regulated the expression of Spry1, an inhibitory protein of the receptor tyrosine kinase (RTK) signaling pathway. Furthermore, immunoprecipitation-mass spectrometry (IP-MS) and co-immunoprecipitation (Co-IP) analysis indicated that SPRY1 binds to nuclear factor kappa B1 (NF-κB1) to prevent nuclear translocation of p65, inhibit activation of NF-κB signaling, prevent excessive inflammatory reaction in the testis, and protect the integrity of the blood-testis barrier. In view of this newly identified Dmrt1- Spry1-NF-κB axis mechanism in the regulation of testicular immune homeostasis, our study opens new avenues for the prevention and treatment of male reproductive diseases in humans and livestock.

Diverse changes in shipping emissions around the Western Pacific ports under the coeffect of the epidemic and fuel oil policy.

The Western Pacific Ocean (the WPO), as one of the busiest shipping areas in the world, holds a complex water traffic network. In 2020, the International Maritime Organization (IMO) low-sulfur fuel regulations were implemented globally, while the COVID-19 outbreak influenced shipping activities together. This study aimed to assess the combined impact of epidemics and low-sulfur fuel policies on ship emissions, as well as their environmental effects on the WPO. The ship emission model based on the Automatic Identification System (AIS) data was applied to analyze the monthly emission variations during 2018-2020. It was found that the epidemic had obvious diverse influences on the coastal ports in the WPO. Overall, shipping emissions declined by 15 %-30 % in the first half of 2020 compared with those in 2019 due to the COVID-19 lockdown, whereas they rebounded in the second half as a result of trade recovery. The pollutants discharged per unit of cargo by ships rose after the large-range lockdown. China's multiphase domestic emission control areas (DECAs) and the IMO global low-sulfur fuel regulation have greatly reduced SO2 emissions from ships and caused them to "bypass and come back" to save fuel costs around emission control areas from 2018 to 2020. Based on satellite data and land-based measurements, it was found that the air quality over sea water and coastal cities has shown a positive response to changes in ship-emitted NOx and SO2. Our results reveal that changes in shipping emissions during typical periods, depending on their niches in the complex port traffic network, call for further efforts for cleaner fuel oils, optimized ECA and ship lane coordination in the future. Shipping related air pollutions during the later economic recovery also needs to be addressed after international scale standing-by events.

Preoperative SARS-CoV-2 infection increases risk of early postoperative cardiovascular complications following noncardiac surgery.

As the coronavirus disease 2019 (COVID-19) pandemic progresses to an endemic phase, a greater number of patients with a history of COVID-19 will undergo surgery. Major adverse cardiovascular and cerebrovascular events (MACE) are the primary contributors to postoperative morbidity and mortality; however, studies assessing the relationship between a previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and postoperative MACE outcomes are limited. Here, we analyzed retrospective data from 457,804 patients within the N3C Data Enclave, the largest national, multi-institutional data set on COVID-19 in the United States. However, 7.4% of patients had a history of COVID-19 before surgery. When comorbidities, age, race, and risk of surgery were controlled, patients with preoperative COVID-19 had an increased risk for 30-day postoperative MACE. MACE risk was influenced by an interplay between COVID-19 disease severity and time between surgery and infection; in those with mild disease, MACE risk was not increased even among those undergoing surgery within 4 wk following infection. In those with moderate disease, risk for postoperative MACE was mitigated 8 wk after infection, whereas patients with severe disease continued to have elevated postoperative MACE risk even after waiting for 8 wk. Being fully vaccinated decreased the risk for postoperative MACE in both patients with no history of COVID-19 and in those with breakthrough COVID-19 infection. Together, our results suggest that a thorough assessment of the severity, vaccination status, and timing of SARS-CoV-2 infection must be a mandatory part of perioperative stratification.NEW & NOTEWORTHY With an increasing proportion of patients undergoing surgery with a prior history of COVID-19, it is crucial to understand the impact of SARS-CoV-2 infection on postoperative cardiovascular/cerebrovascular risk. Our work assesses a large, national, multi-institutional cohort of patients to highlight that COVID-19 infection increases risk for postoperative major adverse cardiovascular and cerebrovascular events (MACE). MACE risk is influenced by an interplay between disease severity and time between infection and surgery, and full vaccination reduces the risk for 30-day postoperative MACE. These results highlight the importance of stratifying time-to-surgery guidelines based on disease severity.

Integrated bioinformatics analysis identifies shared immune changes between ischemic stroke and COVID 19.

Although COVID-19 is primarily a respiratory disease, its neurological complications, such as ischemic stroke (IS), have aroused growing concerns and reports. However, the molecular mechanisms that underlie IS and COVID-19 are not well understood. Therefore, we implemented transcriptomic analysis from eight GEO datasets consist of 1191 samples to detect common pathways and molecular biomarkers in IS and COVID-19 that help understand the linkage between them. Differentially expressed genes (DEGs) were detected for IS and COVID-19 separately for finding shared mechanisms and we found that immune-related pathways were outlined with statistical significance. JAK2, which was identified as a hub gene, was supposed to be a potential therapeutic gene targets during the immunological process of COVID-19 and IS. Besides, we found a decrease in the proportion of CD8+ T and T helper 2 cells in the peripheral circulation of both COVID and IS patients, and NCR3 expression was significantly correlated with this change. In conclusion, we demonstrated that transcriptomic analyses reported in this study could make a deeper understanding of the common mechanism and might be promising for effective therapeutic for IS and COVID-19.

The Bivalent COVID-19 Booster Immunization after Three Doses of Inactivated Vaccine Augments the Neutralizing Antibody Response against Circulating Omicron Sublineages.

A fourth dose of a COVID-19 vaccine has been recommended by a number of authorities due to waning immunity over time and the emergence of immune-escaping variants. Here, we evaluated the safety and immunogenicity of the bivalent BV-01-B5 or V-01D-351 or the prototype V-01 for heterologous boosting in three-dose inactivated COVID-19 vaccine (ICV) recipients, in comparison with ICV homologous boosting. One pilot study (NCT05583357) included 20 participants randomized at 1:1, either receiving V-01D-351 or CoronaVac. The other one (NCT05585567) recruited 36 participants randomized at 2:1, either receiving BV-01-B5 or V-01, respectively. BV-01-B5, V-01D-351, and V-01 were safe and well-tolerated as heterologous booster shots after three doses of ICV, with adverse reactions predominantly being mild and moderate in severity, similar to the safety profile of ICV boosters. The bivalent V-01D-351 and BV-01-B5 and prototype V-01 booster demonstrated remarkable cross-reactive immunogenicity against the prototype and multiple emerging variants of concern (VOCs), with the geometric mean ratio (versus CoronaVac) in particular being 31.3 (500 vs. 16), 12.0 (192 vs. 16) and 8.5 (136 vs.16) against BA.4/5 14 days after the booster, respectively. Taken together, the modified bivalent-formulation V-01 boosters induced robust neutralizing responses against multiple Omicron sublineages, better than V-01 and remarkably superior to ICV booster, without compromising the safety and tolerability.

Guanylate-binding protein 1 restricts avian coronavirus infectious bronchitis virus-infected HD11 cells.

The Infectious Bronchitis Virus (IBV), a coronavirus, is a key avian pathogen that causes acute and highly infectious viral respiratory diseases. IBV is an enveloped, positive-sense RNA virus, and the host factors that restrict infection and replication of the virus remain poorly understood. Guanylate-binding protein 1 (GBP1), an interferon-gamma (IFN-γ)-inducible guanosine triphosphatase (GTPase), is a major player in host immunity and provides defense against viral replication. However, the role of chicken GBP1 (chGBP1) in the IBV-life cycle is not well understood. Therefore, this study aimed to reveal the potential role of IFN-γ-induced chGBP1 in mediating host anti-IBV infection responses. We identified the host restriction factor, chGBP1, in IBV-infected chicken macrophages HD11 cell lines. We showed that chGBP1 was upregulated by treatment with both IFN-γ and IBV in HD11 cells. chGBP1 inhibited IBV replication in a dose-dependent manner and enhanced IFN-γ anti-IBV activity. Importantly, the GTPase domain of chGBP1 played a pivotal role in its anti-IBV activity. Furthermore, chGBP1 interacts with IBV Nucleocapsids protein to degrade IBV-N protein through the autophagy pathway. Taken together, our results demonstrate a critical role of chGBP1 in anti-IBV in macrophages HD11 cells.

Alterations in bile acids as metabolic signatures in the patients with human adenovirus type 7 infection.

Objectives: The changes in metabolism by human adenovirus (HAdV) infection was unclear. The potential mechanism of HAdV-7 causing acute respiratory tract infection was explored. Methods: Totally 35 patients with HAdV-7 infection, 32 asymptomatic cases with HAdV-7 and 14 healthy controls were enrolled from an outbreak of HAdV-7 in the army. The serum samples were analyzed by untargeted and targeted metabolomics. The effects of differential metabolites were verified on HAdV-7 replication in an A549 cell line. Results: The untargeted metabolomics analysis revealed more significant changes in the classes of sphingolipids, polyketides, glycerolipids, fatty acyls, and carboxylic acids and their derivatives in the patients with HAdV-7 than in healthy controls. Two key metabolic pathways of secondary and primary bile acid biosynthesis were noted from pathway enrichment analysis. Targeted metabolomics analysis showed that the levels of unconjugated bile acids in the patients were significantly lower, while the levels of glyco- and tauro- conjugated bile acids in patients and asymptomatic cases were higher than those in the healthy controls. The profiles of cytokines and peripheral lymphocyte subsets obviously varied at different levels of bile acids, with significant differences after HAdV-7 infection. A cell verification test demonstrated that the replication of HAdV-7 significantly reduced when GCDCA and TCA were added. Conclusion: Bile acids inhibited HAdV-7 replication in vitro. Alterations in bile acids was metabolic signatures of HAdV-7 infected subjects, and our results suggested bile acids might play protective roles against HAdV-7 infection.

Early Improvement of Acute Respiratory Distress Syndrome in Patients With COVID-19 in the Intensive Care Unit: Retrospective Analysis.

BACKGROUND: Since the start of the COVID-19 pandemic, there have been over 2 million deaths globally. Acute respiratory distress syndrome (ARDS) may be the main cause of death. OBJECTIVE: This study aimed to describe the clinical features, outcomes, and ARDS characteristics of patients with COVID-19 admitted to the intensive care unit (ICU) in Chongqing, China. METHODS: The epidemiology of COVID-19 from January 21, 2020, to March 15, 2020, in Chongqing, China, was analyzed retrospectively, and 75 ICU patients from two hospitals were included in this study. On day 1, 56 patients with ARDS were selected for subgroup analysis, and a modified Poisson regression was performed to identify predictors for the early improvement of ARDS (eiARDS). RESULTS: Chongqing reported a 5.3% case fatality rate for the 75 ICU patients. The median age of these patients was 57 (IQR 25-75) years, and no bias was present in the sex ratio. A total of 93% (n=70) of patients developed ARDS during ICU stay, and more than half had moderate ARDS. However, most patients (n=41, 55%) underwent high-flow nasal cannula oxygen therapy, but not mechanical ventilation. Nearly one-third of patients with ARDS improved (arterial blood oxygen partial pressure/oxygen concentration >300 mm Hg) in 1 week, which was defined as eiARDS. Patients with eiARDS had a higher survival rate and a shorter length of ICU stay than those without eiARDS. Age (<55 years) was the only variable independently associated with eiARDS, with a risk ratio of 2.67 (95% CI 1.17-6.08). CONCLUSIONS: A new subphenotype of ARDS-eiARDS-in patients with COVID-19 was identified. As clinical outcomes differ, the stratified management of patients based on eiARDS or age is highly recommended.

The support dilemma of stroke inpatients and family caregivers under COVID-19 prevention and control: a qualitative study in China.

China has implemented a strict isolation system in hospitals since the COVID-19 pandemic, that adversely affected the psychology of inpatients and their caregivers. Face-to-face, semi-structured interviews with 22 stroke inpatients from two municipal hospitals were conducted to explore the psychological, emotional and related support needs of stroke inpatients and their family caregivers under this environment. Results which showed that external support for stroke inpatients and their family caregivers was insufficient highlight the necessity for developing specific nursing interventions that meet the psychological and emotional needs of inpatients and the caregivers.

Network characteristics and stock liquidity:Evidence from the UK

This article examines the effect of the Engle-Granger (E-G) price spillover network characteristics on firm's stock liquidity with a longitudinal dataset of FTSE 350 from 2006 to 2021. We find that the subprime crisis, European debt sovereign crisis, British Brexit and COVID-19 caused dramatic network structure change. We also find that firms with higher centrality are likely to suffer from more or greater price shocks leading to lower stock liquidity. Finally, the robust of our results has also been identified, and a general framework for network characteristics and stock liquidity has been established to some extent.

Inhibitors of HIV-1 and Cathepsin L Proteases Identified from the Insect Gall of Hypericum kouytchense.

Hypericum kouytchense Lévl is a semi-evergreen plant of the Hypericaceae family. Its roots and seeds have been used in a number of traditional remedies for antipyretic, detoxification, anti-inflammatory, antimicrobial and antiviral functions. However, to date, no bioactivity compounds have been characterized from the insect gall of H. kouytchens. In this study, we evaluated the antiviral activities of different extracts from the insect gall of H. kouytchen against cathepsin L, HIV-1 and renin proteases and identified the active ingredients using UPLC-HRMS. Four different polar extracts (HW, H30, H60 and H85) of the H. kouytchense insect gall exhibited antiviral activities with IC50 values of 10.0, 4.0, 3.2 and 17.0 µg/mL against HIV-1 protease; 210.0, 34.0, 24.0 and 30.0 µg/mL against cathepsin L protease; and 180.0, 65.0, 44.0 and 39.0 µg/mL against human renin, respectively. Ten compounds were identified and quantified in the H. kouytchense insect gall extracts. Epicatechin, eriodictyol and naringenin chalcone were major ingredients in the extracts with contents ranging from 3.9 to 479.2 µg/mg. For HIV-1 protease, seven compounds showed more than 65% inhibition at a concentration of 1000.0 µg/mL, especially for hypericin and naringenin chalcone with IC50 values of 1.8 and 33.0 µg/mL, respectively. However, only hypericin was active against cathepsin L protease with an IC50 value of 17100.0 µg/mL, and its contents were from 0.99 to 11.65 µg/mg. Furthermore, we attempted to pinpoint the interactions between the active compounds and the proteases using molecular docking analysis. Our current results imply that the extracts and active ingredients could be further formulated and/or developed for potential prevention and treatment of HIV or SARS-CoV-2 infections.

Individual bat viromes reveal the co-infection, spillover and emergence risk of potential zoonotic viruses (preprint)

Bats are reservoir hosts for many zoonotic viruses. Despite this, relatively little is known about the diversity and abundance of viruses within bats at the level of individual animals, and hence the frequency of virus co-infection and inter-species transmission. Using an unbiased meta-transcriptomics approach we characterised the mammalian associated viruses present in 149 individual bats sampled from Yunnan province, China. This revealed a high frequency of virus co-infection and species spillover among the animals studied, with 12 viruses shared among different bat species, which in turn facilitates virus recombination and reassortment. Of note, we identified five viral species that are likely to be pathogenic to humans or livestock, including a novel recombinant SARS-like coronavirus that is closely related to both SARS-CoV-2 and SARS-CoV, with only five amino acid differences between its receptor-binding domain sequence and that of the earliest sequences of SARS-CoV-2. Functional analysis predicts that this recombinant coronavirus can utilize the human ACE2 receptor such that it is likely to be of high zoonotic risk. Our study highlights the common occurrence of inter-species transmission and co-infection of bat viruses, as well as their implications for virus emergence.

Chicken interferon-induced transmembrane protein 1 promotes replication of coronavirus infectious bronchitis virus in a cell-specific manner.

Interferon-induced transmembrane proteins (IFITMs) are broad-spectrum antiviral proteins that inhibit numerous virus infections by impeding viral entry into target cells. However, increasing evidence suggests diverse functions of IFITMs in virus infection, especially with the coronavirus. We analyzed the effect of chicken interferon-induced transmembrane proteins (chIFITMs) on coronavirus infectious bronchitis virus (IBV) infection in vitro. We demonstrated that the antiviral effects of IFITMs are dependent on cell and virus types. The overexpression of chIFITM1 dramatically promoted the replication of IBV Beaudette strain in the chicken hepatocellular carcinoma cell line, LMH. Mechanistically, chIFITMs share roughly the same subcellular localization in different host cells, and overexpressed of chIFITM1 have no effect of viral attachment and entry. Further studies revealed that mutations of amino acids at key positions (60KSRD63, 68KDFV71) in the intracellular loop domain (CIL) caused loss of the promoted function. Interaction with downstream proteins in co-response to viral infection could be the primary reason behind variable functions of chIFITM1 in different cells. In all, our study explored the functions of chIFITMs in viral infection from a new perspective.

Dual Inhibition of HIV-1 and Cathepsin L Proteases by Sarcandra glabra.

The COVID-19 pandemic continues to impose a huge threat on human health due to rapid viral mutations. Thus, it is imperative to develop more potent antivirals with both prophylactic and treatment functions. In this study, we screened for potential antiviral compounds from Sarcandra glabra (SG) against Cathepsin L and HIV-1 proteases. A FRET assay was applied to investigate the inhibitory effects and UPLC-HRMS was employed to identify and quantify the bioactive components. Furthermore, molecular docking was carried out to get a glimpse of the binding of active compounds to the proteases. Our results showed that the SG extracts (SGW, SG30, SG60, and SG85) inhibited HIV-1 protease with an IC50 of 0.003~0.07 mg/mL and Cathepsin L protease with an IC50 of 0.11~0.26 mg/mL. Fourteen compounds were identified along with eight quantified from the SG extracts. Chlorogenic acid, which presented in high content in the extracts (12.7~15.76 µg/mg), possessed the most potent inhibitory activity against HIV-1 protease (IC50 = 0.026 mg/mL) and Cathepsin L protease (inhibition: 40.8% at 0.01 mg/mL). Thus, SG extracts and the active ingredients could potentially be used to prevent/treat viral infections, including SARS-CoV-2, due to their dual-inhibition functions against viral proteases.

A Heterologous V-01 or Variant-Matched Bivalent V-01D-351 Booster following Primary Series of Inactivated Vaccine Enhances the Neutralizing Capacity against SARS-CoV-2 Delta and Omicron Strains.

Immune escape of emerging SARS-CoV-2 variants of concern (VOCs) and waning immunity over time following the primary series suggest the importance and necessity of booster shot of COVID-19 vaccines. With the aim to preliminarily evaluate the potential of heterologous boosting, we conducted two pilot studies to evaluate the safety and immunogenicity of the V-01 or a bivalent V-01D-351 (targeting Delta and Beta strain) booster after 5-7 months of the primary series of inactivated COVID-9 vaccine (ICV). A total of 77 participants were enrolled, with 20 participants in the V-01D-351 booster study, and 27, 30 participants in the age stratified participants of V-01 booster study. The safety results showed that V-01 or V-01D-351 was safe and well-tolerated as a heterologous booster shot, with overall adverse reactions predominantly being absent or mild in severity. The immunogenicity results showed that the heterologous prime-boost immunization with V-01 or bivalent V-01D-351 booster induced stronger humoral immune response as compared with the homologous booster with ICV. In particular, V-01D-351 booster showed the highest pseudovirus neutralizing antibody titers against prototype SARS-CoV-2, Delta and Omicron BA.1 strains at day 14 post boosting, with GMTs 22.7, 18.3, 14.3 times higher than ICV booster, 6.2, 6.1, 3.8 times higher than V-01 booster (10 µg), and 5.2, 3.8, 3.5 times higher than V-01 booster (25 µg), respectively. The heterologous V-01 booster also achieved a favorable safety and immunogenicity profile in older participants. Our study has provided evidence for a flexible roll-out of heterologous boosters and referential approaches for variant-specific vaccine boosters, with rationally conserved but diversified epitopes relative to primary series, to build herd immunity against the ongoing pandemic.