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2.
Antiviral Res ; 205: 105381, 2022 Sep.
Article in English | MEDLINE | ID: covidwho-1982553

ABSTRACT

SARS-CoV-2 has raised the alarm to search for effective therapy for this virus. To date several vaccines have been approved but few available drugs reported recently still need approval from FDA. Remdesivir was approved for emergency use only. In this report, the SARS-CoV-2 3CLpro was expressed and purified. By using a FRET-based enzymatic assay, we have screened a library consisting of more than 300 different niclosamide derivatives and identified three molecules JMX0286, JMX0301, and JMX0941 as potent allosteric inhibitors against SARS-CoV-2 3CLpro, with IC50 values similar to that of known covalent inhibitor boceprevir. In a cell-based antiviral assay, these inhibitors can inhibit the virus growth with EC50 in the range of 2-3 µM. The mechanism of action of JMX0286, JMX0301, and JMX0941 were characterized by enzyme kinetics, affinity binding and protein-based substrate digestion. Molecular docking, molecular dynamics (MD) simulations and hydration studies suggested that JMX0286, JMX0301, JMX0941 bind specifically to an allosteric pocket of the SARS-CoV-2 3CL protease. This study provides three potent compounds for further studies.


Subject(s)
COVID-19 , SARS-CoV-2 , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , COVID-19/drug therapy , Coronavirus 3C Proteases , Cysteine Endopeptidases/metabolism , Humans , Molecular Docking Simulation , Molecular Dynamics Simulation , Peptide Hydrolases/metabolism , Protease Inhibitors/chemistry , Protease Inhibitors/pharmacology , Viral Nonstructural Proteins
3.
Research (Wash D C) ; 2022: 9864089, 2022.
Article in English | MEDLINE | ID: covidwho-1979971

ABSTRACT

Due to the rapid spread of coronavirus disease 2019 (COVID-19), there is an urgent requirement for the development of additional diagnostic tools for further analysis of the disease. The isolated nanobody Nb11-59 binds to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor-binding domain (RBD) with high affinity to neutralize the virus and block the angiotensin-converting enzyme 2- (ACE2-) RBD interaction. Here, we introduce a novel nanobody-based radiotracer named 68Ga-Nb1159. The radiotracer retained high affinity for the RBD and showed reliable radiochemical characteristics both in vitro and in vivo. Preclinical positron emission tomography (PET) studies of 68Ga-Nb1159 in mice revealed its rapid clearance from circulation and robust uptake into the renal and urinary systems. Fortunately, 68Ga-Nb1159 could specifically reveal the distribution of the RBD in mice. This study also helped to evaluate the pharmacodynamic effects of the neutralizing nanobody. Moreover, 68Ga-Nb1159 may be a promising tool to explore the distribution of the RBD and improve the understanding of the virus. In particular, this study identified a novel molecular radioagent and established a reliable evaluation method for specifically investigating the RBD through noninvasive and visual PET technology.

4.
Iran J Sci Technol Trans A Sci ; : 1-6, 2022 Aug 08.
Article in English | MEDLINE | ID: covidwho-1976894

ABSTRACT

This study aims to explore the clinical characteristics of the patients with novel coronavirus pneumonia (COVID-19) during rehabilitation. One hundred and twelve confirmed patients were enrolled, while 72 were females (64.3%) and 40 were males (35.7%). The age of the patients was 51.63 ± 4.07 years old. Those patients were divided into mild group, moderate group and severe group based on lesion volume and proportion of total lesion on CT images. The age, gender, past medical history, finger pulse oxygen (SPO2), heart rate (HR) and body temperature and other clinical characteristics of patients were collected. Lesion volume was measured by CT. Compared with mild group, age, lesion volume and total lesion proportion in moderate group were significantly higher. Age, lesion volume and total lesion proportion in severe group were also higher than those in moderate group. Age and past medical history were the risk factors for the lesion volume of COVID-19. Older the patient has larger CT lesion range (R = 0.232, P = 0.045). Without past medical history or combination of post-medical history, the COVID-19 patients had smaller CT lesion ranges, and the history of previous cardiovascular disease and pulmonary disease was important risk factors for the larger CT lesion ranges. The patients who were older or combined with chronic diseases, especially cardiovascular diseases, respiratory disease and diabetes, tended to have the larger lesions. Age and past medical history of patients with COVID-19 period are significantly related to the lesion volume and total lesion proportion on CT images.

5.
mBio ; : e0199622, 2022 Aug 04.
Article in English | MEDLINE | ID: covidwho-1973798

ABSTRACT

The continuous emergence of SARS-CoV-2 variants with increased transmission and immune evasion has caused breakthrough infections in the vaccinated population. It is important to determine the threshold of neutralizing antibody titers (NT50) that permit breakthrough infections in humans. Here, we tested the neutralization titers of vaccinated patients who contracted Delta variant. All 64 patients with Delta breakthrough infections exhibited NT50 of less than 70. When the breakthrough sera were tested against USA-WA1/2020 (a strain isolated in late January 2020), 82.8%, 15.6%, and 1.6% of them had the NT50 ranges of <20, 20 to 50, and 50 to 69, respectively. When the same breakthrough sera were tested against Delta-spike SARS-CoV-2, 68.7%, 26.6%, and 4.7% of them had the NT50 ranges of <20, 20 to 50, and 50 to 69, respectively. Overall, the results suggest NT50 of 70 as a potential neutralizing threshold required to prevent Delta breakthrough infections. These clinical laboratory results have implications in vaccine strategy and public health policy. IMPORTANCE Given that neutralizing antibodies play a key role in protection of SARS-CoV-2 infection, it is important to define the neutralization levels in vaccinated individuals when they contracted breakthrough infections. In this study, we analyzed the neutralization levels from 64 vaccinated patients on days 0 to 5 before they tested positive for Delta breakthrough infections. The neutralization titers in these vaccinated individuals were all lower than 70 when they contracted breakthrough infections. The results suggest a neutralization titer of 70 as the potential threshold required to prevent breakthrough infections of Delta variant.

6.
Emerg Microbes Infect ; 11(1): 1828-1832, 2022 Dec.
Article in English | MEDLINE | ID: covidwho-1960866

ABSTRACT

Distinct SARS-CoV-2 Omicron sublineages have evolved showing increased fitness and immune evasion than the original Omicron variant BA.1. Here, we report the neutralization activity of sera from BNT162b2 vaccinated individuals or unimmunized Omicron BA.1-infected individuals against Omicron sublineages and "Deltacron" variant (XD). BNT162b2 post-dose 3 immune sera neutralized USA-WA1/2020, Omicron BA.1-, BA.2-, BA.2.12.1-, BA.3-, BA.4/5-, and XD-spike SARS-CoV-2s with geometric mean titres (GMTs) of 1335, 393, 298, 315, 216, 103, and 301, respectively; thus, BA.4/5 SARS-CoV-2 spike variant showed the highest propensity to evade vaccine neutralization compared to the original Omicron variants BA.1. BA.1-convalescent sera neutralized USA-WA1/2020, BA.1-, BA.2-, BA.2.12.1-, BA.3-, BA.4/5-, and Deltacron-spike SARS-CoV-2s with GMTs of 15, 430, 110, 109, 102, 25, and 284, respectively. The unique mutation F486V in the BA.4/5 spike contributes to the increased evasion of antibody neutralization by sublineage BA.4/5. The low neutralization titres of vaccinated sera or convalescent sera from BA.1 infected individuals against the emerging and rapidly spreading Omicron BA.4/5 variants provide important results for consideration in the selection of an updated vaccine in the current Omicron wave.Trial registration: ClinicalTrials.gov; identifier: NCT04368728.


Subject(s)
COVID-19 , Viral Vaccines , Antibodies, Neutralizing , Antibodies, Viral , BNT162 Vaccine , COVID-19/prevention & control , COVID-19/therapy , Humans , Immunization, Passive , Membrane Glycoproteins/genetics , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , Viral Envelope Proteins
7.
Nat Commun ; 13(1): 4337, 2022 07 27.
Article in English | MEDLINE | ID: covidwho-1960370

ABSTRACT

We report a live-attenuated SARS-CoV-2 vaccine candidate with (i) re-engineered viral transcription regulator sequences and (ii) deleted open-reading-frames (ORF) 3, 6, 7, and 8 (∆3678). The ∆3678 virus replicates about 7,500-fold lower than wild-type SARS-CoV-2 on primary human airway cultures, but restores its replication on interferon-deficient Vero-E6 cells that are approved for vaccine production. The ∆3678 virus is highly attenuated in both hamster and K18-hACE2 mouse models. A single-dose immunization of the ∆3678 virus protects hamsters from wild-type virus challenge and transmission. Among the deleted ORFs in the ∆3678 virus, ORF3a accounts for the most attenuation through antagonizing STAT1 phosphorylation during type-I interferon signaling. We also developed an mNeonGreen reporter ∆3678 virus for high-throughput neutralization and antiviral testing. Altogether, the results suggest that ∆3678 SARS-CoV-2 may serve as a live-attenuated vaccine candidate and a research tool for potential biosafety level-2 use.


Subject(s)
COVID-19 Vaccines , COVID-19 , Animals , Antiviral Agents , COVID-19/prevention & control , Cricetinae , Humans , Interferons , Mice , SARS-CoV-2/genetics , Vaccines, Attenuated , Virus Replication
8.
Transl Res ; 2022 Jun 08.
Article in English | MEDLINE | ID: covidwho-1937268

ABSTRACT

Development of optimal SARS-CoV-2 vaccines to induce potent, long-lasting immunity and provide cross-reactive protection against emerging variants remains a high priority. Here, we report that a modified porous silicon microparticle (mPSM) adjuvant to SARS-CoV-2 receptor-binding domain (RBD) vaccine activated dendritic cells and generated more potent and durable systemic humoral and type 1 helper T (Th) cell- mediated immune responses than alum-formulated RBD following parenteral vaccination, and protected mice from SARS-CoV-2 and Beta variant challenge. Notably, mPSM facilitated the uptake of SARS-CoV-2 RBD antigens by nasal and airway epithelial cells. Parenteral and intranasal prime and boost vaccinations with mPSM-RBD elicited stronger lung resident T and B cells and IgA responses compared to parenteral vaccination alone, which led to markedly diminished viral loads and inflammation in the lung following SARS-CoV-2 Delta variant challenge. Overall, our results suggest that mPSM is effective adjuvant for SARS-CoV-2 subunit vaccine in both systemic and mucosal vaccinations.

9.
Nat Commun ; 13(1): 3602, 2022 06 23.
Article in English | MEDLINE | ID: covidwho-1900485

ABSTRACT

The newly emerged Omicron SARS-CoV-2 has several distinct sublineages including BA.1, BA.2, and BA.3. BA.1 accounts for the initial surge and is being replaced by BA.2, whereas BA.3 is at a low prevalence at this time. Here we report the neutralization of BNT162b2-vaccinated sera (collected 1 month after dose 3) against the three Omicron sublineages. To facilitate the neutralization testing, we have engineered the complete BA.1, BA.2, or BA.3 spike into an mNeonGreen USA-WA1/2020 SRAS-CoV-2. All BNT162b2-vaccinated sera neutralize USA-WA1/2020, BA.1-, BA.2-, and BA.3-spike SARS-CoV-2s with titers of >20; the neutralization geometric mean titers (GMTs) against the four viruses are 1211, 336, 300, and 190, respectively. Thus, the BA.1-, BA.2-, and BA.3-spike SARS-CoV-2s are 3.6-, 4.0-, and 6.4-fold less efficiently neutralized than the USA-WA1/2020, respectively. Our data have implications in vaccine strategy and understanding the biology of Omicron sublineages.


Subject(s)
COVID-19 , Viral Vaccines , Antibodies, Viral , BNT162 Vaccine , COVID-19/prevention & control , Humans , SARS-CoV-2
10.
Viruses ; 14(6)2022 06 02.
Article in English | MEDLINE | ID: covidwho-1896924

ABSTRACT

A robust serological test to measure neutralizing antibodies against SARS-CoV-2 in biosafety level-2 (BSL-2) laboratories is useful for monitoring antibody response after vaccination or natural infection. The gold standard assay is the conventional plaque reduction neutralization test (PRNT) which requires extensive labor, live viruses, and BSL-3 facilities. Recently, we developed a novel single-round infection fluorescent SARS-CoV-2 virus (SFV) that can be safely used at BSL-2 laboratories for high-throughput neutralization and antiviral testing. In this study, we evaluated the performance of the neutralization test using this SFV with 80 PRNT-positive and 92 PRNT-negative clinical serum or plasma specimens. The SFV neutralization test (SFVNT) has 100% sensitivity and specificity compared to the PRNT. Furthermore, the neutralizing titers generated by the SFVNT and PRNT are highly correlated, with R2 = 0.903 (p < 0.0001). Due to high sensitivity, specificity, accuracy, and reproducibility, the SFVNT can be deployed for the large-scale testing of COVID-19 patients or vaccinated people in general lab settings.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Neutralizing , Antibodies, Viral , COVID-19/diagnosis , COVID-19 Serological Testing , Containment of Biohazards , Humans , Laboratories , Neutralization Tests , Reproducibility of Results
11.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-338339

ABSTRACT

Distinct SARS-CoV-2 Omicron sublineages have evolved showing increased fitness and immune evasion than the original Omicron variant BA.1. Here we report the neutralization activity of sera from BNT162b2 vaccinated individuals or unimmunized Omicron BA.1-infected individuals against Omicron sublineages and “Deltacron” variant (XD). BNT162b2 post-dose 3 immune sera neutralized USA-WA1/2020, Omicron BA.1-, BA.2-, BA.2.12.1-, BA.3-, BA.4/5-, and XD-spike SARS-CoV-2s with geometric mean titers (GMTs) of 1335, 393, 298, 315, 216, 103, and 301, respectively;thus, BA.4/5 SARS-CoV-2 spike variant showed the highest propensity to evade vaccine neutralization compared to the original Omicron variants BA.1. BA.1-convalescent sera neutralized USA-WA1/2020, BA.1-, BA.2-, BA.2.12.1-, BA.3-, BA.4/5-, and Deltacron-spike SARS-CoV-2s with GMTs of 15, 430, 110, 109, 102, 25, and 284, respectively. The low neutralization titers of vaccinated sera or convalescent sera from BA. 1 infected individuals against the emerging and rapidly spreading Omicron BA.4/5 variants provide important results for consideration in the selection of an updated vaccine in the current Omicron wave.

12.
Nat Commun ; 13(1): 2956, 2022 05 26.
Article in English | MEDLINE | ID: covidwho-1864738

ABSTRACT

The Omicron SARS-CoV-2 has several distinct sublineages, among which sublineage BA.1 is responsible for the initial Omicron surge and is now being replaced by BA.2 worldwide, whereas BA.3 is currently at a low frequency. The ongoing BA.1-to-BA.2 replacement underscores the importance to understand the cross-neutralization among the three Omicron sublineages. Here we test the neutralization of BA.1-infected human sera against BA.2, BA.3, and USA/WA1-2020 (a strain isolated in late January 2020). The BA.1-infected sera neutralize BA.1, BA.2, BA.3, and USA/WA1-2020 SARS-CoV-2s with geometric mean titers (GMTs) of 445, 107, 102, and 16, respectively. Thus, the neutralizing GMTs against heterologous BA.2, BA.3, and USA/WA1-2020 are 4.2-, 4.4-, and 28.4-fold lower than the GMT against homologous BA.1, respectively. These findings have implications in COVID-19 vaccine strategy.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Viral , COVID-19 Vaccines , Humans , Neutralization Tests
13.
Oral Radiol ; 38(3): 433-437, 2022 07.
Article in English | MEDLINE | ID: covidwho-1826794

ABSTRACT

Langerhans cell histiocytosis (LCH) is a disease with varied clinic manifestations. The oral symptoms and signs of LCH localized to the jaws are nonspecific, which may lead to misdiagnosis of this disease. The purpose of this paper was to present the case of a 2-year, 4-month-old LCH patient with progressive destruction of jaws caused by the delayed treatment due to the global outbreak of COVID-19. The cone beam CT analysis after an interval of 6 months reminded us the great significance of early diagnosis and treatment of LCH.


Subject(s)
COVID-19 , Histiocytosis, Langerhans-Cell , Child, Preschool , Cone-Beam Computed Tomography , Histiocytosis, Langerhans-Cell/diagnostic imaging , Humans , Infant , Jaw , Male , Time-to-Treatment
14.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-333143

ABSTRACT

The continuous emergence of SARS-CoV-2 variants with increased transmission and immune evasion has caused breakthrough infections in vaccinated population. It is important to determine the threshold of neutralizing antibody titers that permit breakthrough infections. Here we tested the neutralization titers of vaccinated patients who contracted Delta variant. All 75 patients with Delta breakthrough infections exhibited neutralization titers (NT50) of less than 70. Among the breakthrough patients, 76%, 18.7%, and 5.3% of them had the NT50 ranges of <20, 20-50, and 50-69, respectively. These clinical laboratory results have implications in vaccine strategy and public health policy.

15.
NPJ Vaccines ; 7(1): 41, 2022 Apr 08.
Article in English | MEDLINE | ID: covidwho-1783982

ABSTRACT

BNT162b2-elicited human sera neutralize the currently dominant Delta SARS-CoV-2 variant. Here, we report the ability of 20 human sera, drawn 2 or 4 weeks after two doses of BNT162b2, to neutralize USA-WA1/2020 SARS-CoV-2 bearing variant spikes from Delta plus (Delta-AY.1, Delta-AY.2), Delta-∆144 (Delta with the Y144 deletion of the Alpha variant), Lambda, B.1.1.519, Theta, and Mu lineage viruses. Geometric mean plaque reduction neutralization titers against Delta-AY.1, Delta-AY.2, and Mu viruses are slightly lower than against USA-WA1/2020, but all sera neutralize the variant viruses to titers of ≥80, and neutralization titers against the Delta-∆144, Lambda, B.1.1.519 and Theta variants not significantly reduced relative to those against USA-WA1/2020. The susceptibility of Delta plus, Lambda, B.1.1.519, Theta, Mu, and other variants to neutralization by the sera indicates that antigenic change has not led to virus escape from vaccine-elicited neutralizing antibodies and supports ongoing mass immunization with BNT162b2 to control the variants and to minimize the emergence of new variants.

16.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-332769

ABSTRACT

The Omicron SARS-CoV-2 has three distinct sublineages, among which sublineage BA.1 is responsible for the initial Omicron surge and is now being replaced by BA.2 world-wide, whereas BA.3 is currently at a low frequency. The ongoing BA.1-to-BA.2 replacement underscores the importance to understand the cross-neutralization among the three Omicron sublineages. Here we tested the neutralization of BA.1-infected human sera against BA.2, BA.3, and USA/WA1-2020 (a strain isolated in late January 2020). The BA.1-infected sera neutralized BA.1, BA.2, BA.3, and USA/WA1-2020 SARS-CoV-2s with geometric mean titers (GMTs) of 445, 107, 102, and 16, respectively. Thus, the neutralizing GMTs against heterologous BA.2, BA.3, and USA/WA1-2020 were 4.2-, 4.4-, and 28.4-fold lower than the GMT against homologous BA.1, respectively. These findings have implications in COVID-19 vaccine strategy.

17.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-331542

ABSTRACT

The newly emerged Omicron SARS-CoV-2 has 3 distinct sublineages: BA.1, BA.2, and BA.3. BA.1 accounts for the initial surge and is being replaced by BA.2, whereas BA.3 is at a low prevalence at this time. Here we report the neutralization of BNT162b2-vaccinated sera (collected at 1 month after dose 3) against the three Omicron sublineages. To facilitate the neutralization testing, we engineered the complete BA.1, BA.2, or BA.3 spike into an mNeonGreen USA-WA1/2020 SRAS-CoV-2. All BNT162b2-vaccinated sera neutralized USA-WA1/2020, BA.1-, BA.2-, and BA.3-spike SARS-CoV-2s with titers of >20;the neutralization geometric mean titers (GMTs) against the four viruses were 1211, 336, 300, and 190, respectively. Thus, the BA.1-, BA.2-, and BA.3-spike SARS-CoV-2s were 3.6-, 4.0-, and 6.4-fold less efficiently neutralized than the USA-WA1/2020, respectively. Our data have implications in vaccine strategy and understanding the biology of Omicron sublineages.

18.
Cell Host Microbe ; 30(4): 485-488.e3, 2022 04 13.
Article in English | MEDLINE | ID: covidwho-1693797

ABSTRACT

Two doses of the BNT162b2 mRNA vaccine are highly effective against SARS-CoV-2. Here, we tested the antibody neutralization against Omicron SARS-CoV-2 after 2 and 3 doses of BNT162b2. Serum from vaccinated individuals was serially tested for its ability to neutralize wild-type SARS-CoV-2 (USA-WA1/2020) and an engineered USA-WA1/2020 bearing the Omicron spike glycoprotein. At 2 or 4 weeks post dose 2, the neutralization geometric mean titers (GMTs) against the wild-type and Omicron-spike viruses were 511 and 20, respectively; at 1 month post dose 3, the neutralization GMTs increased to 1,342 and 336; and at 4 months post dose 3, the neutralization GMTs decreased to 820 and 171. The data support a 3-dose vaccination strategy and provide a glimpse into the durability of the neutralization response against Omicron.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Neutralizing , Antibodies, Viral , BNT162 Vaccine , COVID-19/prevention & control , Humans , SARS-CoV-2/genetics , Vaccines, Synthetic , mRNA Vaccines
19.
EuropePMC;
Preprint in English | EuropePMC | ID: ppcovidwho-327679

ABSTRACT

We report a live-attenuated SARS-CoV-2 vaccine candidate with (i) re-engineered viral transcriptional regulator sequences and (ii) deleted open-reading-frames (ORF) 3, 6, 7, and 8 (Δ3678). The Δ3678 virus replicates about 7,500-fold lower than wild-type SARS-CoV-2 on primary human airway cultures, but restores its replication on interferon-deficient Vero-E6 cells that are approved for vaccine production. The Δ3678 virus is highly attenuated in both hamster and K18-hACE2 mouse models. A single-dose immunization of the Δ3678 virus protects hamsters from wild-type virus challenge and transmission. Among the deleted ORFs in the Δ3678 virus, ORF3a accounts for the most attenuation through antagonizing STAT1 phosphorylation during type-I interferon signaling. We also developed an mNeonGreen reporter Δ3678 virus for high-throughput neutralization and antiviral testing. Altogether, the results suggest that Δ3678 SARS-CoV-2 may serve as a live-attenuated vaccine candidate and a research tool for potential biosafety level-2 use.

20.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-321376

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to evolve around the world, generating new variants that are of concern based on their potential for altered transmissibility, pathogenicity, and coverage by vaccines and therapeutics. Here we report that 20 BNT162b2 vaccine-elicited human sera neutralize engineered SARS-CoV-2 with a USA-WA1/2020 genetic background (a virus strain isolated in January 2020) and spike glycoproteins from the newly emerged B.1.617.1 (first identified in India) or B.1.525 (first identified in Nigeria) lineages. Geometric mean plaque reduction neutralization titers against the variant viruses, particularly the B.1.617.1 variant, are lower than the titer against USA-WA1/2020 virus, but all sera tested neutralize the variant viruses at titers of at least 40. The susceptibility of the newly emerged B.1.617.1 and B.1.525 variants to BNT162b2 vaccine-elicited neutralization supports mass immunization as a central strategy to end the COVID-19 pandemic across geographies.

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