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1.
Biomed J ; 44(6S1): S8-S14, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1930767

ABSTRACT

BACKGROUND: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) that causes coronavirus disease 2019 (COVID-19) is highly contagious, with a potential to cause large nosocomial outbreaks in the hospital setting. We report the advance deployment of comprehensive, multi-level infection control measures in a 3,700-bed large hospital to prevent nosocomial outbreaks of COVID-19 during the pandemic. METHODS: We implemented a series of dynamic infection control policies during the pandemic. A confirmed COVID-19 case was defined by positive real-time reverse transcriptase-polymerase chain reaction (RT-PCR) assay. All healthcare worker (HCW) having symptoms or close contact with the confirmed case received the RT-PCR test. RESULTS: A total of 5,722 patients were tested in our hospital from January to May 2020. Twenty-five patients were confirmed COVID-19, including two inpatients. A cluster of 4 HCWs with COVID-19 associated with the 2nd inpatient was identified in the early stage of epidemic. Our enhanced traffic control bundling, mask wearing, hand hygiene and environmental cleaning were reinforced after the outbreak. All other confirmed cases were identified at our outdoor quarantine station or epidemic clinic afterwards, and the results of testing for 146 symptomatic HCWs were all negative. CONCLUSIONS: Integrated teamwork, advance deployment of infection control measures and efficient diagnostic testing and response protected HCW and facilities from large SARS-CoV-2 outbreaks and preserved the capacity and function of the health care system during the pandemic.


Subject(s)
COVID-19 , Cross Infection , COVID-19/epidemiology , Cross Infection/prevention & control , Disease Outbreaks/prevention & control , Hospitals , Humans , Infection Control/methods , Pandemics/prevention & control , SARS-CoV-2 , Taiwan/epidemiology
3.
mSphere ; 7(1): e0088321, 2022 02 23.
Article in English | MEDLINE | ID: covidwho-1673356

ABSTRACT

Considering the urgent demand for faster methods to quantify neutralizing antibody titers in patients with coronavirus (CoV) disease 2019 (COVID-19), developing an analytical model or method to replace the conventional virus neutralization test (NT) is essential. Moreover, a "COVID-19 immunity passport" is currently being proposed as a certification for people who travel internationally. Therefore, an enzyme-linked immunosorbent assay (ELISA) was designed to detect severe acute respiratory syndrome CoV 2 (SARS-CoV-2)-neutralizing antibodies in serum, which is based on the binding affinity of SARS-CoV-2 viral spike protein 1 (S1) and the viral spike protein receptor-binding domain (RBD) to antibodies. The RBD is considered the major binding region of neutralizing antibodies. Furthermore, S1 covers the RBD and several other regions, which are also important for neutralizing antibody binding. In this study, we assessed 144 clinical specimens, including those from patients with PCR-confirmed SARS-CoV-2 infections and healthy donors, using both the NT and ELISA. The ELISA results analyzed by spline regression and the two-variable generalized additive model precisely reflected the NT value, and the correlation between predicted and actual NT values was as high as 0.917. Therefore, our method serves as a surrogate to quantify neutralizing antibody titer. The analytic method and platform used in this study present a new perspective for serological testing of SARS-CoV-2 infection and have clinical potential to assess vaccine efficacy. IMPORTANCE Herein, we present a new approach for serological testing for SARS-CoV-2 antibodies using innovative laboratory methods that demonstrate a combination of biology and mathematics. The traditional virus neutralization test is the gold standard method; however, it is time-consuming and poses a risk to medical personnel. Thus, there is a demand for methods that rapidly quantify neutralizing antibody titers in patients with COVID-19 or examine vaccine efficacy at a biosafety level 2 containment facility. Therefore, we used a two-variable generalized additive model to analyze the results of the enzyme-linked immunosorbent assay and found the method to serve as a surrogate to quantify neutralizing antibody titers. This methodology has potential for clinical use in assessing vaccine efficacy.


Subject(s)
Antibodies, Neutralizing/blood , COVID-19/immunology , Enzyme-Linked Immunosorbent Assay , Models, Immunological , Models, Statistical , Neutralization Tests/methods , SARS-CoV-2/immunology , Biomarkers/blood , COVID-19/blood , COVID-19/diagnosis , Case-Control Studies , Humans , Regression Analysis
4.
Lancet Respir Med ; 9(12): 1396-1406, 2021 12.
Article in English | MEDLINE | ID: covidwho-1621134

ABSTRACT

BACKGROUND: MVC-COV1901, a recombinant protein vaccine containing pre-fusion-stabilised spike protein S-2P adjuvanted with CpG 1018 and aluminium hydroxide, has been shown to be well tolerated with a good safety profile in healthy adults aged 20-49 years in a phase 1 trial, and provided a good cellular and humoral immune responses. We present the interim safety, tolerability, and immunogenicity results of a phase 2 clinical trial of the MVC-COV1901 vaccine in Taiwan. METHODS: This is a large-scale, double-blind, randomised, placebo-controlled phase 2 trial done at ten medical centres and one regional hospital in Taiwan. Individuals aged 20 years or older who were generally healthy or had stable pre-existing medical conditions were eligible for enrolment. Exclusion criteria included (but were not limited to) travel overseas within 14 days of screening, intention to travel overseas within 6 months of the screening visit, and the absence of prespecified medical conditions, including immunosuppressive illness, a history of autoimmune disease, malignancy with risk to recur, a bleeding disorder, uncontrolled HIV infection, uncontrolled hepatitis B and C virus infections, SARS-CoV-1 or SARS-CoV-2 infections, an allergy to any vaccine, or a serious medical condition that could interfere with the study. Study participants were randomly assigned (6:1) to receive two doses of either MVC-COV1901 or placebo, administered via intramuscular injection on day 1 and day 29. MVC-COV1901 contained 15 µg of S-2P protein adjuvanted with 750 µg CpG 1018 and 375 µg aluminium hydroxide in a 0·5 mL aqueous solution, and the placebo contained the same volume of saline. Randomisation was done centrally by use of an interactive web response system, stratified by age (≥20 to <65 years and ≥65 years). Participants and investigators were masked to group assignment. The primary outcomes were to evaluate the safety, tolerability, and immunogenicity of MVC-COV1901 from day 1 (the day of the first dose) to day 57 (28 days after the second dose). Safety was assessed in all participants who received at least one dose. Immunogenicity was assessed by measuring geometric mean titres (GMTs) and seroconversion rates of neutralising antibody and antigen-specific IgG in the per-protocol population. This study is registered with ClinicalTrials.gov, NCT04695652. FINDINGS: Of 4173 individuals screened between Dec 30, 2020, and April 2, 2021, 3854 were enrolled and randomly assigned: 3304 to the MVC-COV1901 group and 550 to the placebo group. A total of 3844 participants (3295 in the MVC-COV1901 group and 549 in the placebo group) were included in the safety analysis set, and 1053 participants (903 and 150) had received both doses and were included in the per-protocol immunogenicity analysis set. From the start of this phase 2 trial to the time of interim analysis, no vaccine-related serious adverse events were recorded. The most common solicited adverse events in all study participants were pain at the injection site (2346 [71·2%] of 3295 in the MVC-COV1901 group and 128 [23·3%] of 549 in the placebo group), and malaise or fatigue (1186 [36·0%] and 163 [29·7%]). Fever was rarely reported (23 [0·7%] and two [0·4%]). At 28 days after the second dose of MVC-COV1901, the wild-type SARS-CoV-2 neutralising antibody GMT was 662·3 (95% CI 628·7-697·8; 408·5 IU/mL), the GMT ratio (geometric mean fold increase in titres at day 57 vs baseline) was 163·2 (155·0-171·9), and the seroconversion rate was 99·8% (95% CI 99·2-100·0). INTERPRETATION: MVC-COV1901 has a good safety profile and elicits promising immunogenicity responses. These data support MVC-COV1901 to enter phase 3 efficacy trials. FUNDING: Medigen Vaccine Biologics and Taiwan Centres for Disease Control, Ministry of Health and Welfare.


Subject(s)
Adjuvants, Immunologic , Aluminum Hydroxide , COVID-19 Vaccines/immunology , COVID-19 , HIV Infections , Oligodeoxyribonucleotides , Adult , Aged , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Double-Blind Method , Humans , Middle Aged , SARS-CoV-2 , Taiwan , Young Adult
6.
2021.
Preprint in English | Other preprints | ID: ppcovidwho-296105

ABSTRACT

Summary Background We have assessed the safety and immunogenicity of the COVID-19 vaccine MVC-COV1901, a recombinant protein vaccine containing prefusion-stabilized spike protein S-2P adjuvanted with CpG 1018 and aluminium hydroxide. Methods This is a phase 2, prospective, randomised, double-blind, placebo-controlled, and multi-centre study to evaluate the safety, tolerability, and immunogenicity of the SARS-CoV-2 vaccine candidate MVC-COV1901. The study comprised 3,844 participants of ≥ 20 years who were generally healthy or with stable pre-existing medical conditions. The study participants were randomly assigned in a 6:1 ratio to receive either MVC-COV1901 containing 15 μg of S-2P protein or placebo containing saline. Participants received two doses of MVC-COV1901 or placebo, administered 28 days apart via intramuscular injection. The primary outcomes were to evaluate the safety, tolerability, and immunogenicity of MVC-COV1901 from Day 1 (the day of first vaccination) to Day 57 (28 days after the second dose). Immunogenicity of MVC-COV1901 was assessed through geometric mean titres (GMT) and seroconversion rates (SCR) of neutralising antibody and antigen-specific immunoglobulin. This clinical trial is registered at ClinicalTrials.gov: NCT04695652 . Findings From the start of this phase 2 trial to the time of interim analysis, no vaccine-related Serious Adverse Events (SAEs) were recorded. The most common solicited adverse events across all study participants were pain at the injection site (64%), and malaise/fatigue (35%). Fever was rarely reported (<1%). For all participants in the MVC-COV1901 group, at 28 days after the second dose against wild type SARS-CoV-2 virus, the GMT was 662·3 (408 IU/mL), the GMT ratio was 163·2, and the seroconversion rate was 99·8%. Interpretation MVC-COV1901 shows good safety profiles and promising immunogenicity responses. The current data supports MVC-COV1901 to enter phase 3 efficacy trials and could enable regulatory considerations for Emergency Use Authorisation (EUA). Funding Medigen Vaccine Biologics Corporation and Taiwan Centres for Disease Control.

7.
JMIR Serious Games ; 9(4): e13124, 2021 Nov 22.
Article in English | MEDLINE | ID: covidwho-1547099

ABSTRACT

BACKGROUND: Learning through a 360° virtual reality (VR) or 2D video represents an alternative way to learn a complex medical education task. However, there is currently no consensus on how best to assess the effects of different learning materials on cognitive load estimates, heart rate variability (HRV), outcomes, and experience in learning history taking and physical examination (H&P) skills. OBJECTIVE: The aim of this study was to investigate how learning materials (ie, VR or 2D video) impact learning outcomes and experience through changes in cognitive load estimates and HRV for learning H&P skills. METHODS: This pilot system-design study included 32 undergraduate medical students at an academic teaching hospital. The students were randomly assigned, with a 1:1 allocation, to a 360° VR video group or a 2D video group, matched by age, sex, and cognitive style. The contents of both videos were different with regard to visual angle and self-determination. Learning outcomes were evaluated using the Milestone reporting form. Subjective and objective cognitive loads were estimated using the Paas Cognitive Load Scale, the National Aeronautics and Space Administration Task Load Index, and secondary-task reaction time. Cardiac autonomic function was assessed using HRV measurements. Learning experience was assessed using the AttrakDiff2 questionnaire and qualitative feedback. Statistical significance was accepted at a two-sided P value of <.01. RESULTS: All 32 participants received the intended intervention. The sample consisted of 20 (63%) males and 12 (38%) females, with a median age of 24 (IQR 23-25) years. The 360° VR video group seemed to have a higher Milestone level than the 2D video group (P=.04). The reaction time at the 10th minute in the 360° VR video group was significantly higher than that in the 2D video group (P<.001). Multiple logistic regression models of the overall cohort showed that the 360° VR video module was independently and positively associated with a reaction time at the 10th minute of ≥3.6 seconds (exp B=18.8, 95% CI 3.2-110.8; P=.001) and a Milestone level of ≥3 (exp B=15.0, 95% CI 2.3-99.6; P=.005). However, a reaction time at the 10th minute of ≥3.6 seconds was not related to a Milestone level of ≥3. A low-frequency to high-frequency ratio between the 5th and 10th minute of ≥1.43 seemed to be inversely associated with a hedonic stimulation score of ≥2.0 (exp B=0.14, 95% CI 0.03-0.68; P=.015) after adjusting for video module. The main qualitative feedback indicated that the 360° VR video module was fun but caused mild dizziness, whereas the 2D video module was easy to follow but tedious. CONCLUSIONS: Our preliminary results showed that 360° VR video learning may be associated with a better Milestone level than 2D video learning, and that this did not seem to be related to cognitive load estimates or HRV indexes in the novice learners. Of note, an increase in sympathovagal balance may have been associated with a lower hedonic stimulation score, which may have met the learners' needs and prompted learning through the different video modules. TRIAL REGISTRATION: ClinicalTrials.gov NCT03501641; https://clinicaltrials.gov/ct2/show/NCT03501641.

8.
EClinicalMedicine ; 38: 100989, 2021 Aug.
Article in English | MEDLINE | ID: covidwho-1375926

ABSTRACT

BACKGROUND: This was a phase 1, dose-escalation open-label trial to evaluate the safety and immunogenicity of MVC-COV1901, a SARS-CoV-2 S-2P protein vaccine adjuvanted with aluminum hydroxide and CpG 1018. METHODS: Between September 28 and November 13 2020, 77 participants were screened. Of these, 45 healthy adults from 20 to 49 years of age were to be administered two doses of MVC-COV1901 in doses of 5 µg, 15 µg, or 25 µg of spike protein at 28 days apart. There were 15 participants in each dose group; all were followed for 28 days after the second dose at the time of the interim analysis. Adverse events and laboratory data were recorded for the safety evaluation. Blood samples were collected for humoral, and cellular immune response at various time points. Trial Registration: ClinicalTrials.gov NCT04487210. FINDINGS: Solicited adverse events were mostly mild and similar. No subject experienced fever. After the second dose, the geometric mean titers (GMTs) for SARS-CoV-2 spike-specific immunoglobulin G were 7178.2, 7746.1, 11,220.6 in the 5 µg, 15 µg, and 25 µg dose groups, respectively. The neutralizing activity were detected in both methods. (Day 43 GMTs, 538.5, 993.1, and 1905.8 for pseudovirus; and 33.3, 76.3, and 167.4 for wild-type virus). The cellular immune response induced by MVC-COV1901 demonstrated substantially higher numbers of IFN-γ- producing cells, suggesting a Th1-skewed immune response. INTERPRETATION: The MVC-COV1901 vaccine was well tolerated and elicited robust immune responses and is suitable for further development. FUNDING: Medigen Vaccine Biologics Corporation.

9.
J Microbiol Immunol Infect ; 2021 Jul 21.
Article in English | MEDLINE | ID: covidwho-1336662

ABSTRACT

BACKGROUND/PURPOSE: Superspreading events (SSEs) are pivotal in the spread of SARS-CoV-2. This study aimed to investigate an SSE of COVID-19 in a hospital and explore the transmission dynamics and heterogeneity of SSE. METHODS: We performed contact tracing for all close contacts in a cluster. We did nasopharyngeal or throat swabbing for SARS-CoV-2 by real-time RT-PCR. Environmental survey was performed. The epidemiological and clinical characteristics of the SSE were studied. RESULTS: Patient 1 with congestive heart failure and cellulitis, who had onset of COVID-19 two weeks after hospitalization, was the index case. Patient 1 led to 8 confirmed cases, including four health care workers (HCW). Persons tested positive for SARS-CoV-2 were HCW (n = 4), patient 1's family (n = 2), an accompanying person of an un-infected in-patient (n = 1), and an in-patient admitted before the SSE (n = 1). The attack rate among the HCW was 3.2 % (4/127). Environmental survey confirmed contamination at the bed rails, mattresses, and sink in the room patient 1 stayed, suggesting fomite transmission. The index case's sputum remained positive on illness day 35. Except one asymptomatic patient, at least three patients acquired the infection from the index case at the pre-symptomatic period. The effective reproduction number (Rt) was 0.9 (8/9). CONCLUSION: The host factor (heart failure, longer viral shedding), transmissibility of SARS-CoV-2 (Rt, pre-symptomatic transmission), and possible multiple modes of transmission altogether contributed to the SSE. Rapid response and advance deployment of multi-level protection in hospitals could mitigate COVID-19 transmission to one generation, thereby reducing its impact on the healthcare system.

10.
Pathogens ; 10(6)2021 Jun 13.
Article in English | MEDLINE | ID: covidwho-1270098

ABSTRACT

A total of 15 RT-PCR confirmed COVID-19 patients were admitted to our hospital during the in-itial outbreak in Taiwan. The average time of virus clearance was delayed in seven patients, 24.14 ± 4.33 days compared to 10.25 ± 0.56 days post-symptom onset (PSO) in the other eight pa-tients. There was strong antibody response in patients with viral persistence at the pharynx, with peak values of serum antibody 677.2 ± 217.8 vs. 76.70 ± 32.11 in patients with delayed versus rapid virus clearance. The patients with delayed viral clearance had excessive antibodies of compromised quality in an early stage with the delay in peak virus neutralization efficacy, 34.14 ± 7.15 versus 12.50 ± 2.35 days PSO in patients with rapid virus clearance. Weak antibody re-sponse of patients with rapid viral clearance was also effective, with substantial and comparable neutralization efficacy, 35.70 ± 8.78 versus 41.37 ± 11.49 of patients with delayed virus clearance. Human Cytokine 48-Plex Screening of the serial sera samples revealed elevated concentrations of proinflammatory cytokines and chemokines in a deceased patient with delayed virus clear-ance and severe disease. The levels were comparatively less in the other two patients who suf-fered from severe disease but eventually survived.

11.
mSphere ; 6(2)2021 03 31.
Article in English | MEDLINE | ID: covidwho-1166378

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) carrying the D614G mutation on the spike protein is the predominant circulating variant and is associated with enhanced infectivity. However, whether this dominant variant can potentially spread through the cold chain and whether the spike protein affects virus stability after cold storage remain unclear. To compare the infectivity of two SARS-CoV-2 variants, namely, SARS-CoV-2 variants with spike protein with the D614 mutation (S-D614) and G614 mutation (S-G614), after different periods of refrigeration (4°C) and freezing (-20°C). We also determined the integrity of the viral RNA and the ability of the spike protein to bind angiotensin-converting enzyme 2 (ACE2) after storage at these conditions. The results showed that SARS-CoV-2 was more stable and infectious after storage at -20°C than at 4°C. Particularly, the S-G614 variant was found to be more stable than the S-D614 variant. The spike protein of the S-G614 variant had better binding ability with the ACE2 receptor than that of the S-D614 variant after storage at -20°C for up to 30 days. Our findings revealed that SARS-CoV-2 remains stable and infectious after refrigeration or freezing, and their stability and infectivity up to 30 days depends on the spike variant. Stability and infectivity are related to each other, and the higher stability of S-G614 compared to that of S-D614 may contribute to rapid viral spread of the S-G614 variant.IMPORTANCE It has been observed that variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are more stable and infectious after storage at -20°C than at 4°C. A SARS-CoV-2 S-D614G variant is currently the most dominant variant in circulation and is associated with enhanced infectivity. We compared the stability of two SARS-CoV-2 variants: the early S-D614 variant carrying the D614 spike protein and the new S-G614 variant carrying the G614 spike protein, stored at both 4°C and -20°C for different periods. We observed that SARS-CoV-2 remains stable and infectious after refrigeration or freezing, which further depends on the spike variant, that is, the ability of the spike protein to bind with the ACE2 receptor with higher efficiency. The high stability of the S-G614 variant also explains its rapid spread and infectivity. Therefore, precautions should be taken during and after handling food preserved under cold conditions.


Subject(s)
COVID-19 , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , Cold Temperature , Genetic Fitness/genetics , Humans , Mutation , Protein Stability
12.
PLoS Pathog ; 17(2): e1009352, 2021 02.
Article in English | MEDLINE | ID: covidwho-1105835

ABSTRACT

Serological and plasmablast responses and plasmablast-derived IgG monoclonal antibodies (MAbs) have been analysed in three COVID-19 patients with different clinical severities. Potent humoral responses were detected within 3 weeks of onset of illness in all patients and the serological titre was elicited soon after or concomitantly with peripheral plasmablast response. An average of 13.7% and 3.5% of plasmablast-derived MAbs were reactive with virus spike glycoprotein or nucleocapsid, respectively. A subset of anti-spike (10 of 32) antibodies cross-reacted with other betacoronaviruses tested and harboured extensive somatic mutations, indicative of an expansion of memory B cells upon SARS-CoV-2 infection. Fourteen of 32 anti-spike MAbs, including five anti-receptor-binding domain (RBD), three anti-non-RBD S1 and six anti-S2, neutralised wild-type SARS-CoV-2 in independent assays. Anti-RBD MAbs were further grouped into four cross-inhibiting clusters, of which six antibodies from three separate clusters blocked the binding of RBD to ACE2 and five were neutralising. All ACE2-blocking anti-RBD antibodies were isolated from two recovered patients with prolonged fever, which is compatible with substantial ACE2-blocking response in their sera. Finally, the identification of non-competing pairs of neutralising antibodies would offer potential templates for the development of prophylactic and therapeutic agents against SARS-CoV-2.


Subject(s)
Antibodies, Viral/immunology , COVID-19/immunology , SARS-CoV-2/immunology , Adult , Angiotensin-Converting Enzyme 2/antagonists & inhibitors , Angiotensin-Converting Enzyme 2/immunology , Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/genetics , Antibody-Producing Cells/immunology , Binding Sites , Epitopes , Humans , Immunoglobulin G/immunology , Nucleocapsid/immunology , Spike Glycoprotein, Coronavirus/immunology
13.
J Clin Microbiol ; 58(8)2020 07 23.
Article in English | MEDLINE | ID: covidwho-999208

ABSTRACT

Real-time reverse transcription-PCR (RT-PCR) is currently the most sensitive method to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes coronavirus disease 2019 (COVID-19). However, the correlation between detectable viral RNA and culturable virus in clinical specimens remains unclear. Here, we performed virus culture for 60 specimens that were confirmed to be positive for SARS-CoV-2 RNA by real-time RT-PCR. The virus could be successfully isolated from 12 throat and nine nasopharyngeal swabs and two sputum specimens. The lowest copy number required for virus isolation was determined to be 5.4, 6.0, and 5.7 log10 genome copies/ml sample for detecting the nsp12, E, and N genes, respectively. We further examined the correlation of genome copy number and virus isolation in different regions of the viral genome, demonstrating that culturable specimens are characterized by high copy numbers with a linear correlation observed between copy numbers of amplicons targeting structural and nonstructural regions. Overall, these results indicate that in addition to the copy number, the integrity of the viral genome should be considered when evaluating the infectivity of clinical SARS-CoV-2 specimens.


Subject(s)
Betacoronavirus/growth & development , Betacoronavirus/isolation & purification , Clinical Laboratory Techniques/methods , Coronavirus Infections/diagnosis , Coronavirus Infections/virology , Pneumonia, Viral/diagnosis , Pneumonia, Viral/virology , Virus Cultivation/methods , Betacoronavirus/genetics , COVID-19 , COVID-19 Testing , COVID-19 Vaccines , Correlation of Data , Humans , Nasopharynx/virology , Pandemics , Pharynx/virology , Real-Time Polymerase Chain Reaction/methods , Reverse Transcriptase Polymerase Chain Reaction/methods , SARS-CoV-2
14.
Sci Rep ; 10(1): 20085, 2020 11 18.
Article in English | MEDLINE | ID: covidwho-933722

ABSTRACT

The COVID-19 pandemic is a worldwide health emergency which calls for an unprecedented race for vaccines and treatment. In developing a COVID-19 vaccine, we applied technology previously used for MERS-CoV to produce a prefusion-stabilized SARS-CoV-2 spike protein, S-2P. To enhance immunogenicity and mitigate the potential vaccine-induced immunopathology, CpG 1018, a Th1-biasing synthetic toll-like receptor 9 (TLR9) agonist was selected as an adjuvant candidate. S-2P in combination with CpG 1018 and aluminum hydroxide (alum) was found to be the most potent immunogen and induced high titer of neutralizing antibodies in sera of immunized mice against pseudotyped lentivirus reporter or live wild-type SARS-CoV-2. In addition, the antibodies elicited were able to cross-neutralize pseudovirus containing the spike protein of the D614G variant, indicating the potential for broad spectrum protection. A marked Th1 dominant response was noted from cytokines secreted by splenocytes of mice immunized with CpG 1018 and alum. No vaccine-related serious adverse effects were found in the dose-ranging study in rats administered single- or two-dose regimens of S-2P combined with CpG 1018 alone or CpG 1018 with alum. These data support continued development of CHO-derived S-2P formulated with CpG 1018 and alum as a candidate vaccine to prevent COVID-19 disease.


Subject(s)
COVID-19 Vaccines/immunology , Immunogenicity, Vaccine , Spike Glycoprotein, Coronavirus/immunology , Adjuvants, Immunologic/therapeutic use , Aluminum Hydroxide/therapeutic use , Animals , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , CHO Cells , COVID-19 Vaccines/adverse effects , COVID-19 Vaccines/therapeutic use , Cricetinae , Cricetulus , Cytokines/blood , Cytokines/metabolism , Female , HEK293 Cells , Humans , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Oligodeoxyribonucleotides/therapeutic use , Rats , Rats, Sprague-Dawley , Spleen/immunology , Th1 Cells/immunology
16.
Nat Struct Mol Biol ; 27(10): 950-958, 2020 10.
Article in English | MEDLINE | ID: covidwho-691341

ABSTRACT

The COVID-19 pandemic has had an unprecedented health and economic impact and there are currently no approved therapies. We have isolated an antibody, EY6A, from an individual convalescing from COVID-19 and have shown that it neutralizes SARS-CoV-2 and cross-reacts with SARS-CoV-1. EY6A Fab binds the receptor binding domain (RBD) of the viral spike glycoprotein tightly (KD of 2 nM), and a 2.6-Å-resolution crystal structure of an RBD-EY6A Fab complex identifies the highly conserved epitope, away from the ACE2 receptor binding site. Residues within this footprint are key to stabilizing the pre-fusion spike. Cryo-EM analyses of the pre-fusion spike incubated with EY6A Fab reveal a complex of the intact spike trimer with three Fabs bound and two further multimeric forms comprising the destabilized spike attached to Fab. EY6A binds what is probably a major neutralizing epitope, making it a candidate therapeutic for COVID-19.


Subject(s)
Antibodies, Viral/chemistry , Betacoronavirus/chemistry , Coronavirus Infections/immunology , Pneumonia, Viral/immunology , Spike Glycoprotein, Coronavirus/chemistry , Adult , Angiotensin-Converting Enzyme 2 , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Antibodies, Viral/metabolism , Betacoronavirus/immunology , Betacoronavirus/metabolism , Binding Sites , COVID-19 , Chlorocebus aethiops , Cross Reactions , Cryoelectron Microscopy , Crystallography, X-Ray , Epitopes , Humans , Immunoglobulin Fab Fragments/chemistry , Immunoglobulin Fab Fragments/metabolism , Male , Pandemics , Peptidyl-Dipeptidase A/metabolism , Protein Conformation , Protein Domains , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/metabolism , Vero Cells
17.
Biomed J ; 43(5): 458-461, 2020 10.
Article in English | MEDLINE | ID: covidwho-640807

ABSTRACT

In late 2019, cases of atypical pneumonia caused by a novel coronavirus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were first reported in Wuhan, China. The disease was officially called coronavirus disease 2019 (COVID-19) and has been declared a pandemic disease by the World Health Organization (WHO). The clinical symptoms may include fever, cough, fatigue, headache, and diarrhea. The radiographic features comprise various presentations, including ground-glass opacities, tiny nodules, and consolidation. However, some atypical pathogens related to community-acquired pneumonia (CAP) may share similar presentations. They may be difficult to distinguish according to the clinical presentation and radiographic findings. Recently, there have been several reports reminding physicians to heed the possibility of co-infection with other pathogens in patients diagnosed with COVID-19. We report a COVID-19 patient co-infected with Mycoplasma pneumoniae who recovered well after combination therapy. We propose that all COVID-19 patients should undergo a meticulous screening routine to ensure that they receive adequate treatments.


Subject(s)
COVID-19/diagnosis , COVID-19/virology , Mycoplasma pneumoniae/virology , SARS-CoV-2/pathogenicity , Cough/diagnosis , Cough/virology , Diagnosis, Differential , Diarrhea/complications , Diarrhea/diagnosis , Diarrhea/virology , Fever/complications , Fever/diagnosis , Fever/virology , Humans , Male , Middle Aged
18.
Emerg Microbes Infect ; 9(1): 1457-1466, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-599993

ABSTRACT

Taiwan experienced two waves of imported infections with Coronavirus Disease 2019 (COVID-19). This study aimed at investigating the genomic variation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Taiwan and compared their evolutionary trajectories with the global strains. We performed culture and full-genome sequencing of SARS-CoV-2 strains followed by phylogenetic analysis. A 382-nucleotides deletion in open reading frame 8 (ORF8) was found in a Taiwanese strain isolated from a patient on February 4, 2020 who had a travel history to Wuhan. Patients in the first wave also included several sporadic, local transmission cases. Genomes of 5 strains sequenced from clustered infections were classified into a new clade with ORF1ab-V378I mutation, in addition to 3 dominant clades ORF8-L84S, ORF3a-G251V and S-D614G. This highlighted clade also included some strains isolated from patients who had a travel history to Turkey and Iran. The second wave mostly resulted from patients who had a travel history to Europe and Americas. All Taiwanese viruses were classified into various clades. Genomic surveillance of SARS-CoV-2 in Taiwan revealed a new ORF8-deletion mutant and a virus clade that may be associated with infections in the Middle East, which contributed to a better understanding of the global SARS-CoV-2 transmission dynamics.


Subject(s)
Betacoronavirus/genetics , Coronavirus Infections/virology , Genome, Viral , Pneumonia, Viral/virology , Animals , Betacoronavirus/classification , Betacoronavirus/isolation & purification , COVID-19 , Cell Line , Chlorocebus aethiops , Haemophilus parainfluenzae/isolation & purification , Humans , Middle East , Open Reading Frames , Pandemics , Phylogeny , RNA, Viral , SARS-CoV-2 , Sequence Deletion , Taiwan , Travel , Vero Cells , Virus Cultivation , Whole Genome Sequencing
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