Publications by authors named "Weijin Huang"

93 Publications

Antibody-dependent cellular cytotoxicity response to SARS-CoV-2 in COVID-19 patients.

Signal Transduct Target Ther 2021 Sep 24;6(1):346. Epub 2021 Sep 24.

Division of HIV/AIDS and Sex-transmitted Virus Vaccines, Institute for Biological Product Control, National Institutes for Food and Drug Control (NIFDC), Beijing, China.

Antibody-dependent cellular cytotoxicity (ADCC) responses to viral infection are a form of antibody regulated immune responses mediated through the Fc fragment. Whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) triggered ADCC responses contributes to COVID-19 disease development is currently not well understood. To understand the potential correlation between ADCC responses and COVID-19 disease development, we analyzed the ADCC activity and neutralizing antibody response in 255 individuals ranging from asymptomatic to fatal infections over 1 year post disease. ADCC was elicited by 10 days post-infection, peaked by 11-20 days, and remained detectable until 400 days post-infection. In general, patients with severe disease had higher ADCC activities. Notably, patients who had severe disease and recovered had higher ADCC activities than patients who had severe disease and deceased. Importantly, ADCC activities were mediated by a diversity of epitopes in SARS-COV-2-infected mice and induced to comparable levels against SARS-CoV-2 variants of concern (VOCs) (B.1.1.7, B.1.351, and P.1) as that against the D614G mutant in human patients and vaccinated mice. Our study indicates anti-SARS-CoV-2 ADCC as a major trait of COVID-19 patients with various conditions, which can be applied to estimate the extra-neutralization level against COVID-19, especially lethal COVID-19.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41392-021-00759-1DOI Listing
September 2021

Structural characterization of a neutralizing mAb H16.001, a potent candidate for a common potency assay for various HPV16 VLPs.

NPJ Vaccines 2020 Sep 23;5(1):89. Epub 2020 Sep 23.

Division of HIV/AIDS and Sexually Transmitted Virus Vaccines, National Institutes for Food and Drug Control (NIFDC), No.31 Huatuo Street, Daxing District, 102629, Beijing, China.

With more human papillomavirus (HPV) virus-like particle (VLP) vaccines to hit the market in future, a monoclonal antibody (mAb) with preferably comparable reactivity against vaccines from different expression systems and bioprocesses is urgently needed for the potency characterization. Among all mAbs against HPV16 collected, rabbit mAb H16.001 is potently neutralizing with the highest affinity, recognizes an immune-dominant epitope, and can comparably react with HPV16 vaccines from various sources. Cryo-electron microscopic (cryo-EM) structure demonstrated that 360 H16.001 Fabs could bind to HPV16 capsid in preferable binding manner without steric hindrance between neighboring Fabs, potentially supporting its identification for VLP structural integrity and utility in monitoring VLP structural probity. This structural analysis indicated that mAb H16.001 afforded unbiased potency characterization for various HPV16 vaccines and was potential for use in vaccine regulation practice. This study also showed a model process for selecting suitable mAbs for potency assays of other vaccines.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41541-020-00236-wDOI Listing
September 2020

Safety and immunogenicity of an inactivated COVID-19 vaccine, BBIBP-CorV, in people younger than 18 years: a randomised, double-blind, controlled, phase 1/2 trial.

Lancet Infect Dis 2021 Sep 15. Epub 2021 Sep 15.

Beijing Institute of Biological Products, Beijing, China.

Background: Although SARS-CoV-2 infection often causes milder symptoms in children and adolescents, young people might still play a key part in SARS-CoV-2 transmission. An efficacious vaccine for children and adolescents could therefore assist pandemic control. For further evaluation of the inactivated COVID-19 vaccine candidate BBIBP-CorV, we assessed the safety and immunogenicity of BBIBP-CorV in participants aged 3-17 years.

Methods: A randomised, double-blind, controlled, phase 1/2 trial was done at Shangqiu City Liangyuan District Center for Disease Control and Prevention in Henan, China. In phases 1 and 2, healthy participants were stratified according to age (3-5 years, 6-12 years, or 13-17 years) and dose group. Individuals with a history of SARS-CoV-2 or SARS-CoV infection were excluded. All participants were randomly assigned, using stratified block randomisation (block size eight), to receive three doses of 2 μg, 4 μg, or 8 μg of vaccine or control (1:1:1:1) 28 days apart. The primary outcome, safety, was analysed in the safety set, which consisted of participants who had received at least one vaccination after being randomly assigned, and had any safety evaluation information. The secondary outcomes were geometric meant titre (GMT) of the neutralising antibody against infectious SARS-CoV-2 and were analysed based on the full analysis set. This study is registered with www.chictr.org.cn, ChiCTR2000032459, and is ongoing.

Findings: Between Aug 14, 2020, and Sept 24, 2020, 445 participants were screened, and 288 eligible participants were randomly assigned to vaccine (n=216, 24 for each dose level [2/4/8 μg] in each of three age cohorts [3-5, 6-12, and 13-17 years]) or control (n=72, 24 for each age cohort [3-5, 6-12, and 13-17 years]) in phase 1. In phase 2, 810 participants were screened and 720 eligible participants were randomly assigned and allocated to vaccine (n=540, 60 for each dose level [2/4/8 μg] in each of three age cohorts [3-5, 6-12, and 13-17 years]) or control (n=180, 60 for each age cohort [3-5, 6-12, and 13-17 years]). The most common injection site adverse reaction was pain (ten [4%] 251 participants in all vaccination groups of the 3-5 years cohort; 23 [9·1%] of 252 participants in all vaccination groups and one [1·2%] of 84 in the control group of the 6-12 years cohort; 20 [7·9%] of 252 participants in all vaccination groups of the 13-17 years cohort). The most common systematic adverse reaction was fever (32 [12·7%] of 251 participants in all vaccination groups and six [7·1%] of 84 participants in the control group of the 3-5 years cohort; 13 [5·2%] of 252 participants in the vaccination groups and one [1·2%] of 84 in the control group of the 6-12 years cohort; 26 [10·3%] of 252 participants in all vaccination groups and eight [9·5%] of 84 in the control group of the 13-17 years cohort). Adverse reactions were mostly mild to moderate in severity. The neutralising antibody GMT against the SARS-CoV-2 virus ranged from 105·3 to 180·2 in the 3-5 years cohort, 84·1 to 168·6 in the 6-12 years cohort, and 88·0 to 155·7 in the 13-17 years cohort on day 28 after the second vaccination; and ranged from 143·5 to 224·4 in the 3-5 years cohort, 127 to 184·8 in the 6-12 years cohort, and 150·7 to 199 in the 13-17 years cohort on day 28 after the third vaccination.

Interpretation: The inactivated COVID-19 vaccine BBIBP-CorV is safe and well tolerated at all tested dose levels in participants aged 3-17 years. BBIBP-CorV also elicited robust humoral responses against SARS-CoV-2 infection after two doses. Our findings support the use of a 4 μg dose and two-shot regimen BBIBP-CorV in phase 3 trials in the population younger than 18 years to further ascertain its safety and protection efficacy against COVID-19.

Funding: National Program on Key Research Project of China, National Mega projects of China for Major Infectious Diseases, National Mega Projects of China for New Drug Creation, and Beijing Science and Technology Plan.

Translation: For the Chinese translation of the abstract see Supplementary Materials section.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/S1473-3099(21)00462-XDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8443232PMC
September 2021

Unmethylated CpG motif-containing genomic DNA fragments of bacillus calmette-guerin improves immune response towards a DNA vaccine for COVID-19.

Vaccine 2021 Oct 3;39(41):6050-6056. Epub 2021 Sep 3.

Institute for Biological Product Control, National Institutes for Food and Drug Control (NIFDC) and WHO Collaborating Center for Standardization and Evaluation of Biologicals, No.31 Huatuo Street, Daxing District, Beijing 102629, China. Electronic address:

The development of an effective vaccine to control the global coronavirus disease-2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus- 2 (SARS-CoV-2) is of utmost importance. In this study, a synthetic DNA-based vaccine candidate, known as pSV10-SARS-CoV-2, expressing the SARS-CoV-2 spike protein was designed and tested in 39 BALB/c mice with BC01, an adjuvant derived from unmethylated CpG motif-containing DNA fragments from the Bacillus Calmette-Guerin genome. Mice vaccinated with pSV10-SARS-CoV-2 with BC01 produced early neutralizing antibodies and developed stronger humoral and cellular immune responses compared to mice that received the DNA vaccine only. Moreover, sera from mice vaccinated with pSV10-SARS-CoV-2 with BC01 can neutralize certain variants, including 614G, 614G + 472 V, 452R, 483A, 501Y.V2, and B.1.1.7. The results of this study demonstrate that the addition of BC01 to a DNA-vaccine for COVID-19 could elicit more effective neutralizing antibody titers for disease prevention.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vaccine.2021.08.103DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8413458PMC
October 2021

Methods to Identify Immunogenic Peptides in SARS-CoV-2 Spike and Protective Monoclonal Antibodies in COVID-19 Patients.

Small Methods 2021 Jul 19;5(7):2100058. Epub 2021 Jun 19.

Department of Microbiology Immunology & Molecular Genetics University of California Los Angeles Los Angeles CA 90095 USA.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the associated COVID-19 diseases are an emerging threat to global public health. Although considerable scientific research on the immune, especially antibody, responses to SARS-CoV-2 infection have been conducted, additional dominant epitopes and protective antibodies are needed for diagnosis and treatment of COVID-19 patients. Here, two different phage libraries are used to identify immunogenic epitopes across the spike protein and monoclonal antibodies from COVID-19 patients. Three peptides are further characterized in the receptor-binding motif (RBM) and measured their antibody levels in COVID-19 patients, from which one identifies one most immunodominant epitope with the highest antibody response in COVID-19 patients and in immunized mice. More importantly, monoclonal antibodies specifically binding to this peptide isolated from COVID-19 patients have therapeutic potential to neutralize SARS-CoV-2 infection. Thus, the approaches to systemically identify immunogenic peptides and directly identify human monoclonal antibodies from patients will provide useful diagnostic and therapeutic tools for COVID-19 and other emerging infectious diseases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/smtd.202100058DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8420616PMC
July 2021

A broadly neutralizing humanized ACE2-targeting antibody against SARS-CoV-2 variants.

Nat Commun 2021 08 17;12(1):5000. Epub 2021 Aug 17.

CAS Key Laboratory of Microbial Physiological and Metabolic Engineering, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.

The successive emergences and accelerating spread of novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) lineages and evolved resistance to some ongoing clinical therapeutics increase the risks associated with the coronavirus disease 2019 (COVID-19) pandemic. An urgent intervention for broadly effective therapies to limit the morbidity and mortality of COVID-19 and future transmission events from SARS-related coronaviruses (SARSr-CoVs) is needed. Here, we isolate and humanize an angiotensin-converting enzyme-2 (ACE2)-blocking monoclonal antibody (MAb), named h11B11, which exhibits potent inhibitory activity against SARS-CoV and circulating global SARS-CoV-2 lineages. When administered therapeutically or prophylactically in the hACE2 mouse model, h11B11 alleviates and prevents SARS-CoV-2 replication and virus-induced pathological syndromes. No significant changes in blood pressure and hematology chemistry toxicology were observed after injections of multiple high dosages of h11B11 in cynomolgus monkeys. Analysis of the structures of the h11B11/ACE2 and receptor-binding domain (RBD)/ACE2 complexes shows hindrance and epitope competition of the MAb and RBD for the receptor. Together, these results suggest h11B11 as a potential therapeutic countermeasure against SARS-CoV, SARS-CoV-2, and escape variants.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41467-021-25331-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8371079PMC
August 2021

Novel quinolone derivatives targeting human dihydroorotate dehydrogenase suppress Ebola virus infection in vitro.

Antiviral Res 2021 Oct 12;194:105161. Epub 2021 Aug 12.

School of Medicine, Tsinghua University, Beijing, 100084, China. Electronic address:

Ebola virus (EBOV) has emerged as a significant public health concern since the 2013-2016 outbreak in West Africa. Currently, no effective antiviral treatments have been approved for clinical use. Compound 1 RYL-634 is a quinolone-derived compound that can inhibit dihydroorotate dehydrogenase, a rate-limiting enzyme in the de novo pyrimidine synthesis pathway and it exhibited antiviral activity against multiple RNA virus infection. In this study, we evaluated the efficacy of a panel of newly developed compounds based on RYL-634 against EBOV infection. Our data showed that RYL-634 as well as its derivatives are effective against EBOV transcription- and replication-competent virus-like particle (trVLP) infection and authentic EBOV infection in vitro at low nanomolar IC values and relatively high CC. Of note, the new derivative RYL-687 had the lowest IC at approximately 7 nM and was almost 6 times more potent than remdesivir (GS-5734). Exogenous addition of different metabolites in the pyrimidine de novo synthesis pathway confirmed DHODH as the target of RYL-687. These data provide evidence that such quinolone-derived compounds are promising therapeutic candidates against EBOV infection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.antiviral.2021.105161DOI Listing
October 2021

Recombinant chimpanzee adenovirus AdC7 expressing dimeric tandem-repeat spike protein RBD protects mice against COVID-19.

Emerg Microbes Infect 2021 Dec;10(1):1574-1588

Key Laboratory of Tropical Translational Medicine of Ministry of Education, School of Tropical Medicine and Laboratory Medicine, The First Affiliated Hospital, Hainan Medical University, Haikou, People's Republic of China.

A safe and effective vaccine is urgently needed to control the unprecedented COVID-19 pandemic. Four adenovirus-vectored vaccines expressing spike (S) protein have been approved for use. Here, we generated several recombinant chimpanzee adenovirus (AdC7) vaccines expressing S, receptor-binding domain (RBD), or tandem-repeat dimeric RBD (RBD-tr2). We found vaccination via either intramuscular or intranasal route was highly immunogenic in mice to elicit both humoral and cellular immune responses. AdC7-RBD-tr2 showed higher antibody responses compared to either AdC7-S or AdC7-RBD. Intranasal administration of AdC7-RBD-tr2 additionally induced mucosal immunity with neutralizing activity in bronchoalveolar lavage fluid. Either single-dose or two-dose mucosal administration of AdC7-RBD-tr2 protected mice against SARS-CoV-2 challenge, with undetectable subgenomic RNA in lung and relieved lung injury. AdC7-RBD-tr2-elicted sera preserved the neutralizing activity against the circulating variants, especially the Delta variant. These results support AdC7-RBD-tr2 as a promising COVID-19 vaccine candidate.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/22221751.2021.1959270DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8366625PMC
December 2021

Three epitope-distinct human antibodies from RenMab mice neutralize SARS-CoV-2 and cooperatively minimize the escape of mutants.

Cell Discov 2021 Jul 20;7(1):53. Epub 2021 Jul 20.

Division of HIV/AIDS and Sex-transmitted Virus Vaccines, Institute for Biological Product Control, National Institutes for Food and Drug Control (NIFDC) and WHO Collaborating Center for Standardization and Evaluation of Biologicals, Beijing, China.

Coronavirus disease 2019 (COVID-19), a pandemic disease caused by the newly emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused more than 3.8 million deaths to date. Neutralizing antibodies are effective therapeutic measures. However, many naturally occurring mutations at the receptor-binding domain (RBD) have emerged, and some of them can evade existing neutralizing antibodies. Here, we utilized RenMab, a novel mouse carrying the entire human antibody variable region, for neutralizing antibody discovery. We obtained several potent RBD-blocking antibodies and categorized them into four distinct groups by epitope mapping. We determined the involved residues of the epitope of three representative antibodies by cryo-electron microscopy (Cryo-EM) studies. Moreover, we performed neutralizing experiments with 50 variant strains with single or combined mutations and found that the mixing of three epitope-distinct antibodies almost eliminated the mutant escape. Our study provides a sound basis for the rational design of fully human antibody cocktails against SARS-CoV-2 and pre-emergent coronaviral threats.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41421-021-00292-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8290868PMC
July 2021

Lentil lectin derived from exhibit broad antiviral activities against SARS-CoV-2 variants.

Emerg Microbes Infect 2021 Dec;10(1):1519-1529

Division of HIV/AIDS and Sex-Transmitted Virus Vaccines, National Institutes for Food and Drug Control (NIFDC), Beijing, People's Republic of China.

The spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mutated continuously and newly emerging variants escape from antibody-mediated neutralization raised great concern. S protein is heavily glycosylated and the glycosylation sites are relatively conserved, thus glycans on S protein surface could be a target for the development of anti-SARS-CoV-2 strategies against variants. Here, we collected 12 plant-derived lectins with different carbohydrate specificity and evaluated their anti-SARS-CoV-2 activity against mutant strains and epidemic variants using a pseudovirus-based neutralization assay. The -derived lentil lectin which specifically bind to oligomannose-type glycans and GlcNAc at the non-reducing end terminus showed most potent and broad antiviral activity against a panel of mutant strains and variants, including the artificial mutants at N-/O-linked glycosylation site, natural existed amino acid mutants, as well as the epidemic variants B.1.1.7, B.1.351, and P.1. Lentil lectin also showed antiviral activity against SARS-CoV and MERS-CoV. We found lentil lectin could block the binding of ACE2 to S trimer and inhibit SARS-CoV-2 at the early steps of infection. Using structural information and determined N-glycan profile of S trimer, taking together with the carbohydrate specificity of lentil lectin, we provide a basis for the observed broad spectrum anti-SARS-CoV-2 activity. Lentil lectin showed weak haemagglutination activity at 1 mg/mL and no cytotoxicity activity, and no weight loss was found in single injection mouse experiment. This report provides the first evidence that lentil lectin strongly inhibit infection of SARS-COV-2 variants, which should provide valuable insights for developing future anti-SARS-CoV-2 strategies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/22221751.2021.1957720DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8330776PMC
December 2021

Potent and protective IGHV3-53/3-66 public antibodies and their shared escape mutant on the spike of SARS-CoV-2.

Nat Commun 2021 07 9;12(1):4210. Epub 2021 Jul 9.

Institute for Hepatology, National Clinical Research Center for Infectious Disease, Shenzhen Third People's Hospital; The Second Affiliated Hospital, School of Medicine, Southern University of Science and Technology, Shenzhen, Guangdong Province, China.

Neutralizing antibodies (nAbs) to SARS-CoV-2 hold powerful potentials for clinical interventions against COVID-19 disease. However, their common genetic and biologic features remain elusive. Here we interrogate a total of 165 antibodies from eight COVID-19 patients, and find that potent nAbs from different patients have disproportionally high representation of IGHV3-53/3-66 usage, and therefore termed as public antibodies. Crystal structural comparison of these antibodies reveals they share similar angle of approach to RBD, overlap in buried surface and binding residues on RBD, and have substantial spatial clash with receptor angiotensin-converting enzyme-2 (ACE2) in binding to RBD. Site-directed mutagenesis confirms these common binding features although some minor differences are found. One representative antibody, P5A-3C8, demonstrates extraordinarily protective efficacy in a golden Syrian hamster model against SARS-CoV-2 infection. However, virus escape analysis identifies a single natural mutation in RBD, namely K417N found in B.1.351 variant from South Africa, abolished the neutralizing activity of these public antibodies. The discovery of public antibodies and shared escape mutation highlight the intricate relationship between antibody response and SARS-CoV-2, and provide critical reference for the development of antibody and vaccine strategies to overcome the antigenic variation of SARS-CoV-2.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41467-021-24514-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8270942PMC
July 2021

The molecular basis for SARS-CoV-2 binding to dog ACE2.

Nat Commun 2021 07 7;12(1):4195. Epub 2021 Jul 7.

CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.

SARS-CoV-2 can infect many domestic animals, including dogs. Herein, we show that dog angiotensin-converting enzyme 2 (dACE2) can bind to the SARS-CoV-2 spike (S) protein receptor binding domain (RBD), and that both pseudotyped and authentic SARS-CoV-2 can infect dACE2-expressing cells. We solved the crystal structure of RBD in complex with dACE2 and found that the total number of contact residues, contact atoms, hydrogen bonds and salt bridges at the binding interface in this complex are slightly fewer than those in the complex of the RBD and human ACE2 (hACE2). This result is consistent with the fact that the binding affinity of RBD to dACE2 is lower than that of hACE2. We further show that a few important mutations in the RBD binding interface play a pivotal role in the binding affinity of RBD to both dACE2 and hACE2. Our work reveals a molecular basis for cross-species transmission and potential animal spread of SARS-CoV-2, and provides new clues to block the potential transmission chains of this virus.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41467-021-24326-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8263772PMC
July 2021

[Quantitative analysis of nine types of virus-like particles in human papilloma virus bulk by size-exclusion chromatography].

Se Pu 2021 Apr;39(4):424-429

National Institutes for Food and Drug Control, Key Laboratory of National Health Commission for Research on Quality and Standardization of Biotech Products, Key Laboratory of Biological Product Quality Research and Evaluation of National Medical Products Administration, Beijing 102629, China.

Cervical cancer is the fourth most common cancer among women. Human papilloma virus (HPV) is the most common cause of cervical cancer which accounts for 5% of all human cancers and results in about 528000 cases and 266000 deaths every year. HPV vaccines are considered the most effective strategy for the prevention of HPV infection and cervical carcinoma. Since 2006, three prophylactic vaccines against HPV have been available on the market, including bivalent vaccines, quadrivalent vaccines, and nine-valent vaccines. Among them, nine-valent vaccines have been reported to be the most effective. They can prevent 97% of the high-grade pre-cancer lesions. Virus-like particles (VLPs), which are arranged as 360 copies of capsid proteins L1, are the only antigens of the HPV vaccine. Nine-valent HPV vaccines are prepared by mixing nine types of VLPs with adjuvants. Thus, the quality of the VLPs, including their stability and content in the HPV bulk, is very important for developing HPV vaccines. In this study, a method was developed for the determination of the nine types of VLPs (HPV6/11/16/18/31/33/45/52/58) in HPV bulk by size exclusion chromatography (SEC). The parameters of this method were optimized in terms of column brand, pore size of stationary phase particles, buffer concentration, and pH value. SHIMSEN Ankylo SEC-300 column (300 mm×7.8 mm, 3 μm) combined with a buffer aqueous solution containing 300 mmol/L NaCl and 50 mmol/L phosphate (pH 7.0) was utilized to separate the VLPs from the matrix since a narrow peak shape and good repeatability for VLPs could be obtained with this column and mobile phase. The optimized method had a wide linear range, good repeatability (RSDs of peak area were not more than 5.0%), and a satisfactory sensitivity (LOQs in the range of 4.58-15.24 μg/mL). The optimized method was used to determine the VLPs in the HPV bulk. The LOQs of the current method were much lower than the content of the nine types of VLPs in the HPV bulk, indicating that this method was sensitive enough for the determination of the nine types of VLPs in the HPV bulk. The method was also used to determine the VLPs in an HPV bulk that had been stored at 4 ℃ for one week. A decrease in the nine types of VLPs in the range of 10.0%-62.6% was observed after they were stored at 4 ℃ for one week. An HPV vaccine was prepared by mixing the VLPs with an adjuvant. Thereafter, the VLPs were adsorbed on the surface of the adjuvant. The developed method was applied to determine the free VLPs in twelve batches of HPV vaccines from three different manufacturers. No obvious free protein was detected in the twelve batches of the HPV vaccines from the three manufacturers, indicating that VLPs from these manufactures react well with their aluminum adjuvant. Folin-phenol (Lowry assay) is commonly used for the determination of proteins in vaccines. It is based on the reduction of phosphomolybdotungstic mixed acid chromogen in the phosphomolybdotungstic reagent, which results in an absorbance maximum at 650 nm. The Lowry method was sensitive to interfering substances. Most interfering substances caused a lower color yield, while some detergents caused a slight increase in color. To reduce the effect of the interfering substances, a procedure for precipitating the proteins was usually required before the sample was tested. Thus, the Lowry assay is complex, time-consuming, and of low selectivity. Compared to the Lowry method, the method we developed is simpler and more automatic. It is a high-throughput method of determining VLPs. It can be used to determine VLPs in HPV bulk and free VLPs in HPV vaccines.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3724/SP.J.1123.2020.06032DOI Listing
April 2021

The Antigenicity of Epidemic SARS-CoV-2 Variants in the United Kingdom.

Front Immunol 2021 17;12:687869. Epub 2021 Jun 17.

Division of HIV/AIDS and Sex-Transmitted Virus Vaccines, Institute for Biological Product Control, National Institutes for Food and Drug Control (NIFDC) and WHO Collaborating Center for Standardization and Evaluation of Biologicals, Beijing, China.

To determine whether the neutralization activity of monoclonal antibodies, convalescent sera and vaccine-elicited sera was affected by the top five epidemic SARS-CoV-2 variants in the UK, including D614G+L18F+A222V, D614G+A222V, D614G+S477N, VOC-202012/01(B.1.1.7) and D614G+69-70del+N439K, a pseudovirus-neutralization assay was performed to evaluate the relative neutralization titers against the five SARS-CoV-2 variants and 12 single deconvolution mutants based on the variants. In this study, 18 monoclonal antibodies, 10 sera from convalescent COVID-19 patients, 10 inactivated-virus vaccine-elicited sera, 14 mRNA vaccine-elicited sera, nine RBD-immunized mouse sera, four RBD-immunized horse sera, and four spike-encoding DNA-immunized guinea pig sera were tested and analyzed. The N501Y, N439K, and S477N mutations caused immune escape from nine of 18 mAbs. However, the convalescent sera, inactivated virus vaccine-elicited sera, mRNA vaccine-elicited sera, spike DNA-elicited sera, and recombinant RBD protein-elicited sera could still neutralize these variants (within three-fold changes compared to the reference D614G variant). The neutralizing antibody responses to different types of vaccines were different, whereby the response to inactivated-virus vaccine was similar to the convalescent sera.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fimmu.2021.687869DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8247764PMC
July 2021

Prevalence of Hepatitis E Virus Infection among Laboratory Rabbits in China.

Pathogens 2021 Jun 21;10(6). Epub 2021 Jun 21.

Institute for Biological Product Control, National Institutes for Food and Drug Control (NIFDC), Beijing 102629, China.

Hepatitis E virus (HEV) is zoonotic and the leading cause of acute viral hepatitis worldwide. Rabbit HEV can infect humans and is prevalent globally. It is reported that laboratory rabbits are also naturally infected with HEV. Therefore, it is important to investigate in a large scale the prevalence of HEV in laboratory rabbits. Serum samples were collected from 649 laboratory rabbits of 13 different commercial vendors in Beijing, China, from 2017 to 2019, and anti-HEV and HEV antigen (Ag) were tested. Fecal samples were collected from 50 laboratory rabbits from one of the vendors for HEV RNA detection. Six laboratory rabbits with natural HEV infection were euthanized and their liver, kidney, bile and urine samples were collected for HEV RNA quantification. Liver tissues were subjected to histopathology analysis. The overall positive rates of anti-HEV antibodies and HEV-Ag are 2.6% (15/588) and 7.9% (51/649), respectively. HEV RNA was detected in 12.0% (6/50) of the rabbits. High viral load of HEV RNA was detected in liver and bile samples. Liver inflammation was observed. HEV is circulating in laboratory rabbit population in China. Strict screening is crucial to ensure experimental accuracy and prevent zoonotic transmission to research personnel.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/pathogens10060780DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8233994PMC
June 2021

Potent RBD-specific neutralizing rabbit monoclonal antibodies recognize emerging SARS-CoV-2 variants elicited by DNA prime-protein boost vaccination.

Emerg Microbes Infect 2021 Dec;10(1):1390-1403

Department of Infectious Diseases, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, People's Republic of China.

Global concerns arose as the emerged and rapidly spreading SARS-CoV-2 variants might escape host immunity induced by vaccination. In this study, a heterologous prime-boost immunization strategy for COVID-19 was designed to prime with a DNA vaccine encoding wild type (WT) spike protein receptor-binding domain (RBD) followed by S1 protein-based vaccine in rabbits. Four vaccine-elicited rabbit monoclonal antibodies (RmAbs), including 1H1, 9H1, 7G5, and 5E1, were isolated for biophysical property, neutralization potency and sequence analysis. All RmAbs recognized RBD or S1 protein with K in the low nM or sub nM range. 1H1 and 9H1, but neither 7G5 nor 5E1, can bind to all RBD protein variants derived from B.1.351. All four RmAbs were able to neutralize wild type (WT) SARS-CoV-2 strain in pseudovirus assay, and 1H1 and 9H1 could neutralize the SARS-CoV-2 WT authentic virus with IC values of 0.136 and 0.026 μg/mL, respectively. Notably, 1H1 was able to neutralize all 6 emerging SARS-CoV-2 variants tested including D614G, B.1.1.7, B.1.429, P.1, B.1.526, and B.1.351 variants, and 5E1 could neutralize against the above 5 variants except P.1. Epitope binning analysis revealed that 9H1, 5E1 and 1H1 recognized distinct epitopes, while 9H1 and 7G5 may have overlapping but not identical epitope. In conclusion, DNA priming protein boost vaccination was an effective strategy to induce RmAbs with potent neutralization capability against not only SARS-CoV-2 WT strain but also emergent variants, which may provide a new avenue for effective therapeutics and point-of-care diagnostic measures.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/22221751.2021.1942227DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8274519PMC
December 2021

The first Chinese national standards for SARS-CoV-2 neutralizing antibody.

Vaccine 2021 06 19;39(28):3724-3730. Epub 2021 May 19.

Institute for Biological Product Control, National Institutes for Food and Drug Control (NIFDC) and WHO Collaborating Center for Standardization and Evaluation of Biologicals, Beijing, China. Electronic address:

In order to meet the domestic urgent needs of evaluating the immunogenicity of vaccines and the potency testing of therapeutic antibody products against coronavirus disease 2019 (COVID-19), the first Chinese national standards for SARS-CoV-2 neutralizing antibody were established. The potency and stability of the candidate standards were determined by neutralization assay and accelerated degradation study. The stability studies showed that the standards were stable in the short-term. The collaborative study showed that the candidate standards could reduce the variations in neutralization titers between labs and thus improve comparability of neutralizing antibody measurements. Sample 22 has been approved by the Biological Product Reference Standards Sub-Committee of the National Drug Reference Standards Committee as the first Chinese National Standard for Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) neutralizing antibody, with an assigned potency of 1,000 units per milliliter (U/ml). This standard will contribute to the standardized assessment of the quality and efficacy of vaccines and therapeutics for COVID-19 in China.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vaccine.2021.05.047DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8133612PMC
June 2021

A practical method for evaluating the efficacy of EVA-71 vaccine using a hSCARB2 knock-in mouse model.

Emerg Microbes Infect 2021 Dec;10(1):1180-1190

Division of Animal Model Research, Institute for Laboratory Animal Resources, National Institutes for Food and Drug Control (NIFDC), Beijing, People's Republic of China.

Hand-foot-and-mouth disease is a contagious disease common among children under 5 years old worldwide. It is caused by strains of enterovirus, especially EV-A71, which can lead to severe disease. Vaccines are the only way to fight this disease. Accordingly, it is necessary to establish an efficient and accurate methodology to evaluate vaccine efficacy . Here, we established a practical method using a hSCARB2 knock-in mouse model, which was susceptible to EV-A71 infection at 5-6 weeks of age, to directly determine the efficacy of vaccines. Unlike traditional approaches, one-week-old hSCARB2 mice were immunized twice with a licensed vaccine, with an interval of a week. The titre of antibodies was measured after 1 week. Mice at 4 weeks of age were challenged with EV-A71 intraperitoneally and intracranially, respectively. The unimmunized hSCARB2 mice displayed systemic clinical symptoms and succumbed to the disease at a rate of approximately 50%. High viral loads were detected in the lungs, brain, and muscles, accompanied by clear pathological changes. The expression of IL-1β, IL-13, IL-17, and TNF-α was significantly upregulated. By contrast, the immunized group was practically normal and indistinguishable from the control mice. These results indicate that the hSCARB2 knock-in mouse is susceptible to infection in adulthood, and the efficacy of EV-A71 vaccine could be directly evaluated in this mouse model. The method developed here may be used in the development of new vaccines against HFMD or quality control of licensed vaccines.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/22221751.2021.1934558DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8205003PMC
December 2021

Humoral immune response to circulating SARS-CoV-2 variants elicited by inactivated and RBD-subunit vaccines.

Cell Res 2021 07 21;31(7):732-741. Epub 2021 May 21.

School of Pharmaceutical Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing, China.

SARS-CoV-2 variants could induce immune escape by mutations on the receptor-binding domain (RBD) and N-terminal domain (NTD). Here we report the humoral immune response to circulating SARS-CoV-2 variants, such as 501Y.V2 (B.1.351), of the plasma and neutralizing antibodies (NAbs) elicited by CoronaVac (inactivated vaccine), ZF2001 (RBD-subunit vaccine) and natural infection. Among 86 potent NAbs identified by high-throughput single-cell VDJ sequencing of peripheral blood mononuclear cells from vaccinees and convalescents, near half anti-RBD NAbs showed major neutralization reductions against the K417N/E484K/N501Y mutation combination, with E484K being the dominant cause. VH3-53/VH3-66 recurrent antibodies respond differently to RBD variants, and K417N compromises the majority of neutralizing activity through reduced polar contacts with complementarity determining regions. In contrast, the 242-244 deletion (242-244Δ) would abolish most neutralization activity of anti-NTD NAbs by interrupting the conformation of NTD antigenic supersite, indicating a much less diversity of anti-NTD NAbs than anti-RBD NAbs. Plasma of convalescents and CoronaVac vaccinees displayed comparable neutralization reductions against pseudo- and authentic 501Y.V2 variants, mainly caused by E484K/N501Y and 242-244Δ, with the effects being additive. Importantly, RBD-subunit vaccinees exhibit markedly higher tolerance to 501Y.V2 than convalescents, since the elicited anti-RBD NAbs display a high diversity and are unaffected by NTD mutations. Moreover, an extended gap between the third and second doses of ZF2001 leads to better neutralizing activity and tolerance to 501Y.V2 than the standard three-dose administration. Together, these results suggest that the deployment of RBD-vaccines, through a third-dose boost, may be ideal for combating SARS-CoV-2 variants when necessary, especially for those carrying mutations that disrupt the NTD supersite.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41422-021-00514-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8138844PMC
July 2021

Cellular tropism and antigenicity of mink-derived SARS-CoV-2 variants.

Signal Transduct Target Ther 2021 05 17;6(1):196. Epub 2021 May 17.

Division of HIV/AIDS and Sex-transmitted Virus Vaccines, Institute for Biological Product Control, National Institutes for Food and Drug Control (NIFDC) and WHO Collaborating Center for Standardization and Evaluation of Biologicals, Beijing, China.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41392-021-00617-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8127491PMC
May 2021

Functional comparison of SARS-CoV-2 with closely related pangolin and bat coronaviruses.

Cell Discov 2021 Apr 6;7(1):21. Epub 2021 Apr 6.

Division of HIV/AIDS and Sex-transmitted Virus Vaccines, Institute for Biological Product Control, National Institutes for Food and Drug Control (NIFDC) and WHO Collaborating Center for Standardization and Evaluation of Biologicals, No. 31 Huatuo Street, Daxing District, Beijing 102629, China.

The origin and intermediate host for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is yet to be determined. Coronaviruses found to be closely related to SARS-CoV-2 include RaTG13 derived from bat and two clusters (PCoV-GD and PCoV-GX) of coronaviruses identified in pangolin. Here, we studied the infectivity and antigenicity patterns of SARS-CoV-2 and the three related coronaviruses. Compared with the other three viruses, RaTG13 showed almost no infectivity to a variety of cell lines. The two pangolin coronaviruses and SARS-CoV-2 showed similar infectious activity. However, in SARS-CoV-2-susceptible cell lines, the pangolin coronaviruses presented even higher infectivity. The striking difference between the SARS-CoV-2 and pangolin coronaviruses is that the latter can infect porcine cells, which could be partially attributed to an amino acid difference at the position of 498 of the spike protein. The infection by SARS-CoV-2 was mainly mediated by Furin and TMPRSS2, while PCoV-GD and PCoV-GX mainly depend on Cathepsin L. Extensive cross-neutralization was found between SARS-CoV-2 and PCoV-GD. However, almost no cross-neutralization was observed between PCoV-GX and SARS-CoV-2 or PCoV-GD. More attention should be paid to pangolin coronaviruses and to investigate the possibility of these coronaviruses spreading across species to become zoonoses among pigs or humans.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41421-021-00256-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8022302PMC
April 2021

Clofazimine: A Promising Inhibitor of Rabies Virus.

Front Pharmacol 2021 18;12:598241. Epub 2021 Mar 18.

Department of HIV/AIDS and Sex-transmitted Virus Vaccines, National Institutes for Food and Drug Control, Beijing, China.

With an almost 100% mortality rate, rabies virus (RABV) infection is a global concern. Limited post-exposure prophylaxis and lack of an effective treatment necessitate novel antiviral therapies against RABV. Here, using a high-throughput screening (HTS) method developed in our lab, 11 candidates with anti-RABV activity were identified from a library of 767 clinical drugs. Clofazimine (CFZ), an anti-leprosy drug, displayed an EC of 2.28 μM, and SI over 967 against RABV. Investigations into the underlying mechanisms revealed that CFZ targeted viral membrane fusion at the early stages of virus replication. Moreover, CFZ and Clofazimine salicylates (CFZS) exhibited elevated survival rates , compared with the positive control T-705. Thus, this study revealed CFZ as a promising drug against RABV infection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fphar.2021.598241DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8012719PMC
March 2021

SARS-CoV-2 501Y.V2 variants lack higher infectivity but do have immune escape.

Cell 2021 04 23;184(9):2362-2371.e9. Epub 2021 Feb 23.

Division of HIV/AIDS and Sex-transmitted Virus Vaccines, Institute for Biological Product Control, National Institutes for Food and Drug Control (NIFDC) and WHO Collaborating Center for Standardization and Evaluation of Biologicals, No. 31 Huatuo Street, Daxing District, Beijing 102629, China. Electronic address:

The 501Y.V2 variants of SARS-CoV-2 containing multiple mutations in spike are now dominant in South Africa and are rapidly spreading to other countries. Here, experiments with 18 pseudotyped viruses showed that the 501Y.V2 variants do not confer increased infectivity in multiple cell types except for murine ACE2-overexpressing cells, where a substantial increase in infectivity was observed. Notably, the susceptibility of the 501Y.V2 variants to 12 of 17 neutralizing monoclonal antibodies was substantially diminished, and the neutralization ability of the sera from convalescent patients and immunized mice was also reduced for these variants. The neutralization resistance was mainly caused by E484K and N501Y mutations in the receptor-binding domain of spike. The enhanced infectivity in murine ACE2-overexpressing cells suggests the possibility of spillover of the 501Y.V2 variants to mice. Moreover, the neutralization resistance we detected for the 501Y.V2 variants suggests the potential for compromised efficacy of monoclonal antibodies and vaccines.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cell.2021.02.042DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7901273PMC
April 2021

S-Trimer, a COVID-19 subunit vaccine candidate, induces protective immunity in nonhuman primates.

Nat Commun 2021 03 1;12(1):1346. Epub 2021 Mar 1.

Clover Biopharmaceuticals, Chengdu, China.

SARS-CoV-2 is the underlying cause for the COVID-19 pandemic. Like most enveloped RNA viruses, SARS-CoV-2 uses a homotrimeric surface antigen to gain entry into host cells. Here we describe S-Trimer, a native-like trimeric subunit vaccine candidate for COVID-19 based on Trimer-Tag technology. Immunization of S-Trimer with either AS03 (oil-in-water emulsion) or CpG 1018 (TLR9 agonist) plus alum adjuvants induced high-level of neutralizing antibodies and Th1-biased cellular immune responses in animal models. Moreover, rhesus macaques immunized with adjuvanted S-Trimer were protected from SARS-CoV-2 challenge compared to vehicle controls, based on clinical observations and reduction of viral loads in lungs. Trimer-Tag may be an important platform technology for scalable production and rapid development of safe and effective subunit vaccines against current and future emerging RNA viruses.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41467-021-21634-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7921634PMC
March 2021

Publisher Correction: A vaccine targeting the RBD of the S protein of SARS-CoV-2 induces protective immunity.

Nature 2021 Feb;590(7844):E23

Key Laboratory of Human Disease Comparative Medicine, Chinese Ministry of Health, Beijing Key Laboratory for Animal Models of Emerging and Remerging Infectious Diseases, Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences and Comparative Medicine Center, Peking Union Medical College, Beijing, China.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41586-020-03108-4DOI Listing
February 2021

Simultaneous determination of capsid proteins in nine-valent human papilloma virus vaccines by liquid chromatography tandem mass spectrometry.

J Sep Sci 2021 Jan 10;44(2):557-564. Epub 2020 Dec 10.

Shimadzu scientific instrument company, Beijing, P. R. China.

A liquid chromatography-tandem mass spectrometry method was developed to determine nine types of capsid proteins simultaneously in nine-valent human papillomavirus vaccines. Signature peptides were optimized in terms of specificity, repeatability, determination accuracy and sensitivity. As a result, three signature peptides per capsid protein were obtained. The linear calibration curves were achieved in the range of 11.6-373.6 nmol/L (R  > 0.998). Compared to our previous liquid chromatography-tandem mass spectrometry method, the current method was more sensitive (3.18-fold) and it can be used for quality evaluation of nine-valent human papillomavirus vaccines, unlike the previous method, which could only be used for bivalent human papillomavirus vaccines. Then, they were utilized to determine nine types of capsid proteins in nine-valent human papillomavirus vaccines from four different manufactures. Intraday and interday precision values for the determination of capsid proteins in nine-valent human papillomavirus vaccines were less than 6.8 and 9.1%, respectively. Recovery rates of all capsid proteins investigated were in the range of 80-120%. In addition, the current assay was used for determination of free capsid protein in nine-valent human papilloma virus vaccines, and the results were used to evaluate the adsorption rate of the adjuvant.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jssc.202000973DOI Listing
January 2021

Spike-specific circulating T follicular helper cell and cross-neutralizing antibody responses in COVID-19-convalescent individuals.

Nat Microbiol 2021 01 16;6(1):51-58. Epub 2020 Nov 16.

The Baoqing Psychiatric Hospital, Shaoyang, China.

Coronavirus disease 2019 (COVID-19) is caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and individuals with COVID-19 have symptoms that can be asymptomatic, mild, moderate or severe. In the early phase of infection, T- and B-cell counts are substantially decreased; however, IgM and IgG are detectable within 14 d after symptom onset. In COVID-19-convalescent individuals, spike-specific neutralizing antibodies are variable. No specific drug or vaccine is available for COVID-19 at the time of writing; however, patients benefit from treatment with serum from COVID-19-convalescent individuals. Nevertheless, antibody responses and cross-reactivity with other coronaviruses in COVID-19-convalescent individuals are largely unknown. Here, we show that the majority of COVID-19-convalescent individuals maintained SARS-CoV-2 spike S1- and S2-specific antibodies with neutralizing activity against the SARS-CoV-2 pseudotyped virus, and that some of the antibodies cross-neutralized SARS-CoV, Middle East respiratory syndrome coronavirus or both pseudotyped viruses. Convalescent individuals who experienced severe COVID-19 showed higher neutralizing antibody titres, a faster increase in lymphocyte counts and a higher frequency of CXCR3 T follicular help (T) cells compared with COVID-19-convalescent individuals who experienced non-severe disease. Circulating T cells were spike specific and functional, and the frequencies of CXCR3 T cells were positively associated with neutralizing antibody titres in COVID-19-convalescent individuals. No individuals had detectable autoantibodies. These findings provide insights into neutralizing antibody responses in COVID-19-convalescent individuals and facilitate the treatment and vaccine development for SARS-CoV-2 infection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41564-020-00824-5DOI Listing
January 2021

Characterization of neutralizing antibody with prophylactic and therapeutic efficacy against SARS-CoV-2 in rhesus monkeys.

Nat Commun 2020 11 13;11(1):5752. Epub 2020 Nov 13.

Mabwell (Shanghai) Bioscience Co., Ltd, 201210, Shanghai, China.

Efficacious interventions are urgently needed for the treatment of COVID-19. Here, we report a monoclonal antibody (mAb), MW05, with SARS-CoV-2 neutralizing activity by disrupting the interaction of receptor binding domain (RBD) with angiotensin-converting enzyme 2 (ACE2) receptor. Crosslinking of Fc with FcγRIIB mediates antibody-dependent enhancement (ADE) activity by MW05. This activity is eliminated by introducing the LALA mutation to the Fc region (MW05/LALA). Potent prophylactic and therapeutic effects against SARS-CoV-2 are observed in rhesus monkeys. A single dose of MW05/LALA blocks infection of SARS-CoV-2 in prophylactic treatment and clears SARS-CoV-2 in three days in a therapeutic treatment setting. These results pave the way for the development of MW05/LALA as an antiviral strategy for COVID-19.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41467-020-19568-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7666115PMC
November 2020

Safety and immunogenicity of an inactivated SARS-CoV-2 vaccine, BBIBP-CorV: a randomised, double-blind, placebo-controlled, phase 1/2 trial.

Lancet Infect Dis 2021 01 15;21(1):39-51. Epub 2020 Oct 15.

Chinese Center for Disease Control and Prevention, Beijing, China.

Background: The ongoing COVID-19 pandemic warrants accelerated efforts to test vaccine candidates. We aimed to assess the safety and immunogenicity of an inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine candidate, BBIBP-CorV, in humans.

Methods: We did a randomised, double-blind, placebo-controlled, phase 1/2 trial at Shangqiu City Liangyuan District Center for Disease Control and Prevention in Henan Province, China. In phase 1, healthy people aged 18-80 years, who were negative for serum-specific IgM/IgG antibodies against SARS-CoV-2 at the time of screening, were separated into two age groups (18-59 years and ≥60 years) and randomly assigned to receive vaccine or placebo in a two-dose schedule of 2 μg, 4 μg, or 8 μg on days 0 and 28. In phase 2, healthy adults (aged 18-59 years) were randomly assigned (1:1:1:1) to receive vaccine or placebo on a single-dose schedule of 8 μg on day 0 or on a two-dose schedule of 4 μg on days 0 and 14, 0 and 21, or 0 and 28. Participants within each cohort were randomly assigned by stratified block randomisation (block size eight) and allocated (3:1) to receive vaccine or placebo. Group allocation was concealed from participants, investigators, and outcome assessors. The primary outcomes were safety and tolerability. The secondary outcome was immunogenicity, assessed as the neutralising antibody responses against infectious SARS-CoV-2. This study is registered with www.chictr.org.cn, ChiCTR2000032459.

Findings: In phase 1, 192 participants were enrolled (mean age 53·7 years [SD 15·6]) and were randomly assigned to receive vaccine (2 μg [n=24], 4 μg [n=24], or 8 μg [n=24] for both age groups [18-59 years and ≥60 years]) or placebo (n=24). At least one adverse reaction was reported within the first 7 days of inoculation in 42 (29%) of 144 vaccine recipients. The most common systematic adverse reaction was fever (18-59 years, one [4%] in the 2 μg group, one [4%] in the 4 μg group, and two [8%] in the 8 μg group; ≥60 years, one [4%] in the 8 μg group). All adverse reactions were mild or moderate in severity. No serious adverse event was reported within 28 days post vaccination. Neutralising antibody geometric mean titres were higher at day 42 in the group aged 18-59 years (87·7 [95% CI 64·9-118·6], 2 μg group; 211·2 [158·9-280·6], 4 μg group; and 228·7 [186·1-281·1], 8 μg group) and the group aged 60 years and older (80·7 [65·4-99·6], 2 μg group; 131·5 [108·2-159·7], 4 μg group; and 170·87 [133·0-219·5], 8 μg group) compared with the placebo group (2·0 [2·0-2·0]). In phase 2, 448 participants were enrolled (mean age 41·7 years [SD 9·9]) and were randomly assigned to receive the vaccine (8 μg on day 0 [n=84] or 4 μg on days 0 and 14 [n=84], days 0 and 21 [n=84], or days 0 and 28 [n=84]) or placebo on the same schedules (n=112). At least one adverse reaction within the first 7 days was reported in 76 (23%) of 336 vaccine recipients (33 [39%], 8 μg day 0; 18 [21%], 4 μg days 0 and 14; 15 [18%], 4 μg days 0 and 21; and ten [12%], 4 μg days 0 and 28). One placebo recipient in the 4 μg days 0 and 21 group reported grade 3 fever, but was self-limited and recovered. All other adverse reactions were mild or moderate in severity. The most common systematic adverse reaction was fever (one [1%], 8 μg day 0; one [1%], 4 μg days 0 and 14; three [4%], 4 μg days 0 and 21; two [2%], 4 μg days 0 and 28). The vaccine-elicited neutralising antibody titres on day 28 were significantly greater in the 4 μg days 0 and 14 (169·5, 95% CI 132·2-217·1), days 0 and 21 (282·7, 221·2-361·4), and days 0 and 28 (218·0, 181·8-261·3) schedules than the 8 μg day 0 schedule (14·7, 11·6-18·8; all p<0·001).

Interpretation: The inactivated SARS-CoV-2 vaccine, BBIBP-CorV, is safe and well tolerated at all tested doses in two age groups. Humoral responses against SARS-CoV-2 were induced in all vaccine recipients on day 42. Two-dose immunisation with 4 μg vaccine on days 0 and 21 or days 0 and 28 achieved higher neutralising antibody titres than the single 8 μg dose or 4 μg dose on days 0 and 14.

Funding: National Program on Key Research Project of China, National Mega projects of China for Major Infectious Diseases, National Mega Projects of China for New Drug Creation, and Beijing Science and Technology Plan.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/S1473-3099(20)30831-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7561304PMC
January 2021
-->