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1.
Vaccines (Basel) ; 10(5)2022 Apr 21.
Article in English | MEDLINE | ID: covidwho-1847411

ABSTRACT

Rapid development and deployment of vaccines is crucial to control the continuously evolving COVID-19 pandemic. The placebo-controlled phase 3 efficacy trial is still the standard for authorizing vaccines in the majority of the world. However, due to a lack of eligible participants in parts of the world, this has not always been feasible. Recently, the Taiwan Food and Drug Administration, following the consensus of the International Coalition of Medicines Regulatory Authorities (ICMRA), adopted the use of immunobridging studies as acceptable for authorizing COVID-19 vaccines in lieu of efficacy data. Here, we describe a study in which our candidate vaccine, MVC-COV1901, an adjuvanted protein subunit vaccine, has been granted emergency use authorization (EUA) in Taiwan based on a noninferiority immunobridging study. Immunogenicity results from the per protocol immunogenicity (PPI) subset (n = 903) from the MVC-COV1901 phase 2 trial were compared with results from 200 subjects who had received an adenovirus vector vaccine, AstraZeneca ChAdOx nCOV-19 (AZD1222), in a separate study. The lower bound of the 95% confidence interval (CI) of the geometric mean titer (GMT) ratio comparing MVC-COV1901 to AZD1222 was 3.4. The lower bound of the 95% CI of the sero-response rate was 95.5%. Both the GMT ratio and sero-response rate exceeded the criteria established by the Taiwan regulatory authority, leading to EUA approval of MVC-COV1901 in Taiwan.

2.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-329648

ABSTRACT

The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has substantially impacted human health globally. Spike-specific antibody response plays a major role in protection against SARS-CoV-2. Here, we demonstrated that acute SARS-CoV-2 infection elicits rapid and robust spike-binding and ACE2-blocking antibody responses, which wane approximately 11 months after infection. Serological responses were found to be correlated with the frequency of spike-specific memory B cell responses to natural infections. Further, significantly higher spike-binding, ACE2-blocking, and memory B cell responses were detected in patients with fever and pneumonia. Spike-specific antibody responses were found to be greatly affected by spike mutations in emerging variants, especially the Beta and Omicron variants. These results warrant continued surveillance of spike-specific antibody responses to natural infections and highlight the importance of maintaining functional anti-spike antibodies through immunization. Importance As spike protein-specific antibody responses play a major role in protection against SARS-CoV-2, we examined the spike-binding and ACE2-blocking antibody responses in SARS-CoV-2 infection at different time points. We found robust responses following acute infection, which waned approximately 11 months after infection. Further, the serological responses were correlated with the frequency of spike-specific memory B cell responses to natural infections. Patients with fever and pneumonia showed significantly stronger spike-binding, ACE2-blocking antibody, and memory B cell responses. Moreover, the spike-specific antibody responses were substantially affected by the emerging variants, especially the Beta and Omicron variants. These results warrant continued surveillance of spike-specific antibody responses to natural infections and highlight the importance of maintaining functional anti-spike antibodies through immunization.

3.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-329296

ABSTRACT

Background: Rapid development and deployment of vaccine is crucial to control the continuously evolving COVID-19 pandemic. Placebo-controlled phase 3 efficacy trial is still standard for authorizing vaccines in majority of the world. However, due to lack of cases or participants in parts of the world, this has not always been feasible. An alternative to efficacy trial is immunobridging, in which the immune response or correlates of protection of a vaccine candidate is compared against an approved vaccine. Here we describe a case study where our candidate vaccine, MVC-COV1901, has been granted for emergency use authorization (EUA) locally based on the non-inferiority immunobridging process. Methods The per protocol immunogenicity (PPI) subset from the MVC-COV1901 phase 2 trial was used for this study and consisted of 903 subjects who have received two doses of MVC-COV1901 as scheduled in the clinical trial. The comparator set of population consisted of 200 subjects of ≥ 20 years of age who were generally healthy, and have received two doses of AstraZeneca ChAdOx nCOV-19 (AZD1222) recruited from Taoyuan General Hospital, Ministry of Health and Welfare. Results MVC-COV1901 was shown to have a geometric mean titer (GMT) ratio lower bound 95% confidence internal (CI) of 3.4 against the comparator vaccine and a seroconversion rate of 95.5% at the 95% CI lower bound, which both exceeded the criteria set by the Taiwan regulatory authority for EUA approval. These results supported the EUA approval of MVC-COV1901 by the Taiwanese regulatory authority in July 2021. Following the consensus of the International Coalition of Medicines Regulatory Authorities (ICMRA), countries from the Access Consortium has recently adopted the use of immunobridging studies as acceptable for authorizing COVID-19 vaccines in lieu of efficacy data. Conclusion The data presented in the study showed that it is reasonably likely that the vaccine efficacy of MVC-COV1901 is similar or superior to that of AZ. Data could be used in support of further vaccine development and regulatory approval.

6.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-296595

ABSTRACT

We report the interim safety and immunogenicity results in participants administrated with a booster dose of protein subunit vaccine MVC-COV1901 at 12 or 24 weeks after two doses of AZD1222 (ChAdOx1 nCoV-19). In subjects fully vaccinated with two doses of AZD1222, waning antibody immunity was apparent within six months of the second dose of AZD1222. At one month after the MVC-COV1901 booster dose, anti-SARS-CoV-2 spike IgG antibody titers and neutralizing antibody titers were 14- and 8.6-fold increased, respectively, when compared to the titer levels on the day of the booster dose. These interim results support the use of MVC-COV1901 as a heterologous booster for individuals vaccinated with AZD1222.

8.
Nat Commun ; 12(1): 2349, 2021 04 15.
Article in English | MEDLINE | ID: covidwho-1189222

ABSTRACT

Substantial COVID-19 research investment has been allocated to randomized clinical trials (RCTs) on hydroxychloroquine/chloroquine, which currently face recruitment challenges or early discontinuation. We aim to estimate the effects of hydroxychloroquine and chloroquine on survival in COVID-19 from all currently available RCT evidence, published and unpublished. We present a rapid meta-analysis of ongoing, completed, or discontinued RCTs on hydroxychloroquine or chloroquine treatment for any COVID-19 patients (protocol: https://osf.io/QESV4/ ). We systematically identified unpublished RCTs (ClinicalTrials.gov, WHO International Clinical Trials Registry Platform, Cochrane COVID-registry up to June 11, 2020), and published RCTs (PubMed, medRxiv and bioRxiv up to October 16, 2020). All-cause mortality has been extracted (publications/preprints) or requested from investigators and combined in random-effects meta-analyses, calculating odds ratios (ORs) with 95% confidence intervals (CIs), separately for hydroxychloroquine and chloroquine. Prespecified subgroup analyses include patient setting, diagnostic confirmation, control type, and publication status. Sixty-three trials were potentially eligible. We included 14 unpublished trials (1308 patients) and 14 publications/preprints (9011 patients). Results for hydroxychloroquine are dominated by RECOVERY and WHO SOLIDARITY, two highly pragmatic trials, which employed relatively high doses and included 4716 and 1853 patients, respectively (67% of the total sample size). The combined OR on all-cause mortality for hydroxychloroquine is 1.11 (95% CI: 1.02, 1.20; I² = 0%; 26 trials; 10,012 patients) and for chloroquine 1.77 (95%CI: 0.15, 21.13, I² = 0%; 4 trials; 307 patients). We identified no subgroup effects. We found that treatment with hydroxychloroquine is associated with increased mortality in COVID-19 patients, and there is no benefit of chloroquine. Findings have unclear generalizability to outpatients, children, pregnant women, and people with comorbidities.


Subject(s)
COVID-19/drug therapy , COVID-19/mortality , Chloroquine/adverse effects , Hydroxychloroquine/adverse effects , Pregnancy Complications, Infectious/mortality , Adult , COVID-19/complications , COVID-19/virology , Child , Chloroquine/administration & dosage , Combined Modality Therapy/adverse effects , Combined Modality Therapy/methods , Comorbidity , Female , Humans , Hydroxychloroquine/administration & dosage , International Cooperation , Odds Ratio , Patient Participation/statistics & numerical data , Pregnancy , Pregnancy Complications, Infectious/drug therapy , Pregnancy Complications, Infectious/virology , Randomized Controlled Trials as Topic/statistics & numerical data , SARS-CoV-2
9.
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
10.
J Microbiol Immunol Infect ; 54(5): 816-829, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1096116

ABSTRACT

BACKGROUND/PURPOSE: Our study goals were to evaluate the diagnostic performance of four anti-SARS-CoV-2 antibodies tests and the differences in dynamic immune responses between COVID-19 patients with and without pneumonia. METHODS: We collected 184 serum samples from 70 consecutively qRT-PCR-confirmed COVID-19 patients at four participating hospitals from 23 January 2020 to 30 September 2020. COVID-19 pneumonia was defined as the presence of new pulmonary infiltration. Serum samples were grouped by the duration after symptom onset on a weekly basis for antibody testing and analysis. The four immunoassays: Beckman SARS-CoV-2 IgG/IgM (Beckman Test), Siemens (ADVIA Centaur®) SARS-CoV-2 Total (COV2T) (Siemens Test), SBC COVID-19 IgG ELISA (SBC Test) and EliA SARS-CoV-2-Sp1 IgG/IgM/IgA P2 Research (EliA Test) were used for detecting the SARS-CoV-2 specific antibodies. RESULTS: The sensitivity of all tests reached 100% after 42 days of symptom onset. Siemens Test, the only test detecting total anti-SARS-CoV-2 antibodies, had the best performance in the early diagnosis of COVID-19 infection (day 0-7: 77%; day 8-14: 95%) compared to the other 3 serological tests. All tests showed 100% specificity except SBC Test (98%). COVID-19 patients with pneumonia had significantly higher testing signal values than patients without pneumonia (all p values < 0.05, except EliA IgM Test). However, Siemens Test and SBC Test had highest probability in early prediction of the presence of COVID-19 pneumonia. CONCLUSION: Chronological analysis of immune response among COVID-19 patients with different serological tests provides important information in the early diagnosis of SARS-CoV-2 infection and prediction of the risk of pneumonia after infection.


Subject(s)
COVID-19 Testing/methods , COVID-19/diagnosis , Immunoassay/methods , Pneumonia/diagnosis , SARS-CoV-2/isolation & purification , Adult , Antibodies, Viral/blood , Antibody Formation , Early Diagnosis , Enzyme-Linked Immunosorbent Assay , False Positive Reactions , Female , Humans , Immunoglobulin A/blood , Immunoglobulin G/blood , Immunoglobulin M/blood , Male , Middle Aged , Retrospective Studies , Sensitivity and Specificity , Serologic Tests , Taiwan
11.
J Microbiol Immunol Infect ; 54(3): 522-526, 2021 Jun.
Article in English | MEDLINE | ID: covidwho-1056931

ABSTRACT

To determine clinical performance of the single-target SARS-CoV-2 orf 1 ab reverse transcription-insulated isothermal PCR (RT-iiPCR) assay, the positive percentage agreement between this assay and a laboratory real-time RT-PCR assay was 96.8% (30 of 31; 95% confidence interval [CI], 90.5%-100%) and the negative percentage agreement was 97.1% (67 of 69; 95% CI, 93.1%-100%).


Subject(s)
COVID-19 Nucleic Acid Testing/methods , COVID-19/diagnosis , SARS-CoV-2/isolation & purification , Adult , Aged , Female , Humans , Male , Middle Aged , RNA, Viral/isolation & purification , Reverse Transcriptase Polymerase Chain Reaction , Sensitivity and Specificity , Young Adult
12.
PLoS One ; 15(12): e0242763, 2020.
Article in English | MEDLINE | ID: covidwho-954687

ABSTRACT

OBJECTIVE: In this study, we evaluated the efficacy of hydroxychloroquine (HCQ) against coronavirus disease 2019 (COVID-19) via a randomized controlled trial (RCT) and a retrospective study. METHODS: Subjects admitted to 11 designated public hospitals in Taiwan between April 1 and May 31, 2020, with COVID-19 diagnosis confirmed by pharyngeal real-time RT-PCR for SARS-CoV-2, were randomized at a 2:1 ratio and stratified by mild or moderate illness. HCQ (400 mg twice for 1 d or HCQ 200 mg twice daily for 6 days) was administered. Both the study and control group received standard of care (SOC). Pharyngeal swabs and sputum were collected every other day. The proportion and time to negative viral PCR were assessed on day 14. In the retrospective study, medical records were reviewed for patients admitted before March 31, 2020. RESULTS: There were 33 and 37 cases in the RCT and retrospective study, respectively. In the RCT, the median times to negative rRT-PCR from randomization to hospital day 14 were 5 days (95% CI; 1, 9 days) and 10 days (95% CI; 2, 12 days) for the HCQ and SOC groups, respectively (p = 0.40). On day 14, 81.0% (17/21) and 75.0% (9/12) of the subjects in the HCQ and SOC groups, respectively, had undetected virus (p = 0.36). In the retrospective study, 12 (42.9%) in the HCQ group and 5 (55.6%) in the control group had negative rRT-PCR results on hospital day 14 (p = 0.70). CONCLUSIONS: Neither study demonstrated that HCQ shortened viral shedding in mild to moderate COVID-19 subjects.


Subject(s)
COVID-19/drug therapy , Hydroxychloroquine/adverse effects , Hydroxychloroquine/therapeutic use , Safety , Adult , Female , Humans , Male , Middle Aged , Retrospective Studies , Standard of Care , Treatment Outcome , Young Adult
13.
Emerg Microbes Infect ; 9(1): 2157-2168, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-780276

ABSTRACT

This multicenter, retrospective study included 346 serum samples from 74 patients with coronavirus disease 2019 (COVID-19) and 194 serum samples from non-COVID-19 patients to evaluate the performance of five anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody tests, i.e. two chemiluminescence immunoassays (CLIAs): Roche Elecsys® Anti-SARS-CoV-2 Test (Roche Test) and Abbott SARS-CoV-2 IgG (Abbott Test), and three lateral flow immunoassays (LFIAs): Wondfo SARS-CoV-2 Antibody Test (Wondfo Test), ASK COVID-19 IgG/IgM Rapid Test (ASK Test), and Dynamiker 2019-nCoV IgG/IgM Rapid Test (Dynamiker Test). We found high diagnostic sensitivities (%, 95% confidence interval [CI]) for the Roche Test (97.4%, 93.4-99.0%), Abbott Test (94.0%, 89.1-96.8%), Wondfo Test (91.4%, 85.8-94.9%), ASK Test (97.4%, 93.4-99.0%), and Dynamiker Test (90.1%, 84.3-94.0%) after >21 days of symptom onset. Meanwhile, the diagnostic specificity was 99.0% (95% CI, 96.3-99.7%) for the Roche Test, 97.9% (95% CI, 94.8-99.2%) for the Abbott Test, and 100.0% (95% CI, 98.1-100.0%) for the three LFIAs. Cross-reactivity was observed in sera containing anti-cytomegalovirus (CMV) IgG/IgM antibodies and autoantibodies. No difference was observed in the time to seroconversion detection of the five serological tests. Specimens from patients with COVID-19 pneumonia demonstrated a shorter seroconversion time and higher chemiluminescent signal than those without pneumonia. Our data suggested that understanding the dynamic antibody response after COVID-19 infection and performance characteristics of different serological test are crucial for the appropriate interpretation of serological test result for the diagnosis and risk assessment of patient with COVID-19 infection.


Subject(s)
Antibodies, Viral/immunology , Betacoronavirus/immunology , Coronavirus Infections/diagnosis , Coronavirus Infections/immunology , Immunoassay/methods , Luminescent Measurements/methods , Pneumonia, Viral/diagnosis , Pneumonia, Viral/immunology , Adult , Aged , Antibodies, Viral/blood , Betacoronavirus/genetics , COVID-19 , Coronavirus Infections/epidemiology , Coronavirus Infections/virology , Cross Reactions/immunology , Female , Humans , Immunoassay/standards , Luminescent Measurements/standards , Male , Middle Aged , Pandemics , Pneumonia, Viral/epidemiology , Pneumonia, Viral/virology , Reproducibility of Results , SARS-CoV-2 , Seroconversion , Serologic Tests , Severity of Illness Index , Taiwan/epidemiology
14.
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
15.
Biomed J ; 43(4): 314-317, 2020 08.
Article in English | MEDLINE | ID: covidwho-436885

ABSTRACT

By the request of the Minister of Health and Welfare, NHRI Biobank was assigned to establish a COVID-19 biobank in early Feb, 2020 to collect COVID-19 patients' blood samples for Taiwan researchers and industries in an emergent way. It was set up in less than 3 weeks and quickly opened for application. By August 5, 2020, this COVID-19 biobank has collected 165 blood samples of 110 patients from more than 10 hospitals across north, middle and south part of Taiwan, including both COVID-19 (+) and (-) pneumonia patients. This biobank can provide applicants with biosamples, such as serum, DNA and RNA, and also the clinical and genomic data, so as to accelerate the COVID-19 treatment and prevention research in Taiwan. This COID-19 biobank already received 15 applications. It has become the most important research resource for the COVID-19 pandemic in Taiwan, including new screening reagents, disease mechanism, the variable human responses and epidemic preventions. Since it is publicly available for both academic and industrial applicants.


Subject(s)
Betacoronavirus/pathogenicity , Biological Specimen Banks , Coronavirus Infections/virology , Pneumonia, Viral/virology , COVID-19 , Coronavirus Infections/drug therapy , Coronavirus Infections/epidemiology , Coronavirus Infections/pathology , Hospitals , Humans , Pandemics , Pneumonia, Viral/epidemiology , Pneumonia, Viral/pathology , SARS-CoV-2 , Taiwan/epidemiology
16.
Int J Infect Dis ; 96: 464-466, 2020 Jul.
Article in English | MEDLINE | ID: covidwho-426401

ABSTRACT

We report the case of a patient who had travelled to Japan and who presented mild respiratory symptoms during the COVID-19 outbreak period. There was transient existence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA in his oropharynx. The RNA was absent in the six respiratory specimens that were subsequently tested. An anti-SARS-CoV-2 antibody response was absent in the acute and convalescent sera. The reported case indicates that transient colonization of SARS-CoV-2 in the upper respiratory tract is possible without inciting any antibody response against the virus.


Subject(s)
Antibodies, Viral/immunology , Betacoronavirus/genetics , Coronavirus Infections , Pandemics , Pneumonia, Viral , RNA, Viral/genetics , Respiratory System , Adult , Betacoronavirus/immunology , COVID-19 , Coronavirus Infections/epidemiology , Coronavirus Infections/immunology , Disease Outbreaks , Humans , Japan , Male , Pneumonia, Viral/epidemiology , Pneumonia, Viral/immunology , SARS-CoV-2
17.
J Microbiol Immunol Infect ; 53(3): 488-492, 2020 Jun.
Article in English | MEDLINE | ID: covidwho-31181

ABSTRACT

An increase of Ct values was 0.9 per day in 2 cases of COVID-19 treated with lopinavir/ritonavir (LPV/r), an increase was 1.0 per day in 3 cases without LPV/r through illness day 1-10, indicating that LPV/r did not shorten the duration of SARS CoV-2 shedding.


Subject(s)
Antiviral Agents/therapeutic use , Betacoronavirus/drug effects , Coronavirus Infections/drug therapy , Coronavirus Infections/pathology , Lopinavir/therapeutic use , Pneumonia, Viral/drug therapy , Pneumonia, Viral/pathology , Ritonavir/therapeutic use , Virus Shedding/drug effects , COVID-19 , Chloroquine/therapeutic use , Drug Combinations , Female , Humans , Male , Middle Aged , Pandemics , Ribavirin/therapeutic use , SARS-CoV-2 , Taiwan
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