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1.
PLoS One ; 18(4): e0282854, 2023.
Article in English | MEDLINE | ID: covidwho-2287065

ABSTRACT

The COVID-19 pandemic has drawn attention to the strategic responses of Chinese firms on digital transformation and led to a call for enhancing competitive advantage via accelerating digital transformation. Besides the physical health issue, the pandemic has triggered an extraordinary social and economic crisis in which service industries have been attacked hard. In this situation, firms are meeting increasing competitive pressure, which urges them to achieve better performance with the help of digital transformation. Based on the technology-organization-environment framework and dynamic capabilities theory, this research proposed two studies with two methods, including a structural equation model and a regression discontinuity design with a fixed-effect model. The findings suggest digital transformation mediates the relationship between competitive pressure and firm performance among Chinese small- and medium-sized enterprises and large firms after the outbreak of COVID-19, respectively. It confirms that digital transformation is a practical strategic decision for Chinese service firms to respond to increasing competitive pressure in the COVID-19 pandemic. Besides, the results also illustrate the moderating effects of absorptive, innovative, and adaptive capability on the relationship between digital transformation and firm performance among large firms.


Subject(s)
COVID-19 , Commerce , Industry , Humans , COVID-19/epidemiology , Pandemics
2.
Front Immunol ; 13: 898151, 2022.
Article in English | MEDLINE | ID: covidwho-1933687

ABSTRACT

Safe and effective vaccines against SARS-CoV-2 for children are urgently needed. Here we aimed to assess the safety and immunogenicity of an inactivated COVID-19 vaccine candidate, WIBP-CorV, in participants aged 3-17 years. A randomized, double-blind, placebo-controlled, phase 1/2 clinical trial was conducted in Henan Province, China, in healthy children aged 3-17 years. 240 participants in phase 1 trial and 576 participants in phase 2 trial were randomly assigned to vaccine or control with an age de-escalation in three cohorts (3-5, 6-12 and 13-17 years) and dose-escalation in three groups (2.5, 5.0 and 10.0µg/dose), and received 3 intramuscular injections at day 0, 28, and 56. WIBP-CorV showed a promising safety profile with approximately 17% adverse reactions within 30 days after injection and no grade 3 or worse adverse events. The most common adverse reaction was injection site pain, followed by fever, which were mild and self-limiting. The geometric mean titers of neutralizing antibody ranged from 102.2 to 1065.5 in vaccinated participants at 28 days after the third vaccination, and maintained at a range of 14.3 to 218.2 at day 180 after the third vaccination. WIBP-CorV elicited significantly higher titers of neutralizing antibody in the cohort aged 3-5 years than the other two cohorts. There were no detectable antibody responses in all alum-only groups. Taken together, our data demonstrate that WIBP-CorV is safe and well tolerated at all tested doses in participants aged 3-17 years, and elicited robust humoral responses against SARS-CoV-2 lasted for at least 6 months after the third vaccination. This study is ongoing and is registered with www.chictr.org.cn, ChiCTR2000031809.


Subject(s)
COVID-19 , Vaccines , Antibodies, Neutralizing , COVID-19/prevention & control , COVID-19 Vaccines/adverse effects , Child , Double-Blind Method , Humans , SARS-CoV-2
3.
Cell Discov ; 7(1): 82, 2021 Sep 07.
Article in English | MEDLINE | ID: covidwho-1397862

ABSTRACT

The pandemic of COVID-19 caused by SARS-CoV-2 has raised a new challenges to the scientific and industrious fields after over 1-year spread across different countries. The ultimate approach to end the pandemic is the timely application of vaccines to achieve herd immunity. Here, a novel SARS-CoV-2 receptor-binding domain (RBD) homodimer was developed as a SARS-CoV-2 vaccine candidate. Formulated with aluminum adjuvant, RBD dimer elicited strong immune response in both rodents and non-human primates, and protected mice from SARS-CoV-2 challenge with significantly reducing viral load and alleviating pathological injury in the lung. In the non-human primates, the vaccine could prevent majority of the animals from SARS-CoV-2 infection in the respiratory tract and reduce lung damage. In addition, antibodies elicited by this vaccine candidate showed cross-neutralization activities to SARS-CoV-2 variants. Furthermore, with our expression system, we provided a high-yield RBD homodimer vaccine without additional biosafety or special transport device supports. Thus, it may serve as a safe, effective, and low-cost SARS-CoV-2 vaccine candidate.

4.
Nat Commun ; 12(1): 4887, 2021 08 09.
Article in English | MEDLINE | ID: covidwho-1349665

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a novel coronavirus that is spreading rapidly, which seriously impacts global public health and economy. Thus, developing effective drugs remains urgent. We identify two potent antibodies, nCoVmab1 and nCoVmab2, targeting the SARS-CoV-2 spike protein receptor-binding domain (RBD) with high affinities from a naïve human phage-displayed Fab library. nCoVmab1 and nCoVmab2 neutralize authentic SARS-CoV-2 with picomolar and nanomolar IC50 values, respectively. No detectable defects of nCoVmab1 and nCoVmab2 are found during the preliminary druggability evaluation. nCoVmab1 could reduce viral titer and lung injury when administered prophylactically and therapeutically in human angiotensin-converting enzyme II (hACE2)-transgenic mice. Therefore, phage display platform could be efficiently used for rapid development of neutralizing monoclonal antibodies (nmabs) with clinical potential against emerging infectious diseases. In addition, we determinate epitopes in RBD of these antibodies to elucidate the neutralizing mechanism. We also convert nCoVmab1 and nCoVmab2 to their germline formats for further analysis, which reveals the contribution of somatic hypermutation (SHM) during nCoVmab1 and nCoVmab2 maturation. Our findings not only provide two highly potent nmabs against SARS-CoV-2 as prophylactic and therapeutic candidates, but also give some clues for development of anti-SARS-CoV-2 agents (e.g., drugs and vaccines) targeting the RBD.


Subject(s)
Antibodies, Neutralizing/therapeutic use , Antibodies, Viral/therapeutic use , COVID-19 Drug Treatment , SARS-CoV-2/drug effects , Angiotensin-Converting Enzyme 2/genetics , Animals , Antibodies, Monoclonal/therapeutic use , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Binding Sites , COVID-19/immunology , COVID-19/pathology , COVID-19/virology , Chlorocebus aethiops , Epitopes/immunology , Humans , Male , Mice , Mice, Transgenic , Protein Binding , Receptors, Virus/drug effects , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus , Vero Cells
5.
EClinicalMedicine ; 38: 101010, 2021 Aug.
Article in English | MEDLINE | ID: covidwho-1300745

ABSTRACT

BACKGROUND: We aimed to assess the safety and immunogenicity of an inactivated vaccine against COVID-19 in Chinese adults aged ≥18 years. METHODS: This is an ongoing randomized, double-blind, placebo-controlled, phase 1/2 clinical trial among healthy adults aged ≥18 years in Henan Province, China. Participants (n = 336 in 18-59 age group and n = 336 in ≥60 age group) were enrolled between April 12 and May 17 2020, and were equally randomized to receive vaccine or placebo (aluminum hydroxide adjuvant) in a three-dose schedule of 2·5, 5, or 10 µg on days 0, 28, and 56. Another 448 adults aged 18-59 years were equally allocated to four groups (a one-dose schedule of 10 µg, and two-dose schedules of 5 µg on days 0 and 14/21/28) and received vaccine or placebo (ratio 3:1 within each group). The primary outcomes were 7-day post-injection adverse reactions and neutralizing antibody titres on days 28 and 90 after the whole-course vaccination. Trial registration: www.chictr.org.cn #ChiCTR2000031809. FINDINGS: The 7-day adverse reactions occurred in 4·8% to 32·1% of the participants in various groups, and most adverse reactions were mild, transient, and self-limiting. Twenty participants reported 68 serious adverse events which were judged to be unrelated to the vaccine. The 90-day post-injection geometric mean titres of neutralizing antibody ranged between 87 (95% CI: 61-125) and 129 (99-169) for three-dose schedule among younger and older adults; 20 (14-27), 53 (38-75), and 44 (32-61) in 5 µg days 0 and 14/21/28 groups, respectively, and 7 (6-9) in one-dose 10 µg group. There were no detectable antibody responses in all placebo groups. INTERPRETATION: The inactivated vaccine against COVID-19 was well tolerated and immunogenic in both younger and older adults. The two-dose schedule of 5 µg on days 0 and 21/28 and three-dose schedules on days 0, 28, and 56 could be further evaluated for long-term safety and efficacy in the phase 3 trials.

6.
Virol Sin ; 36(5): 879-889, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1174014

ABSTRACT

The ongoing coronavirus disease 2019 (COVID-19) pandemic caused more than 96 million infections and over 2 million deaths worldwide so far. However, there is no approved vaccine available for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the disease causative agent. Vaccine is the most effective approach to eradicate a pathogen. The tests of safety and efficacy in animals are pivotal for developing a vaccine and before the vaccine is applied to human populations. Here we evaluated the safety, immunogenicity, and efficacy of an inactivated vaccine based on the whole viral particles in human ACE2 transgenic mouse and in non-human primates. Our data showed that the inactivated vaccine successfully induced SARS-CoV-2-specific neutralizing antibodies in mice and non-human primates, and subsequently provided partial (in low dose) or full (in high dose) protection of challenge in the tested animals. In addition, passive serum transferred from vaccine-immunized mice could also provide full protection from SARS-CoV-2 infection in mice. These results warranted positive outcomes in future clinical trials in humans.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19 , Animals , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , COVID-19/prevention & control , Mice , Mice, Transgenic , Primates , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Vaccines, Inactivated/immunology
7.
Emerg Microbes Infect ; 9(1): 2606-2618, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-944152

ABSTRACT

The ongoing COVID-19 pandemic is causing huge impact on health, life, and global economy, which is characterized by rapid spreading of SARS-CoV-2, high number of confirmed cases and a fatality/case rate worldwide reported by WHO. The most effective intervention measure will be to develop safe and effective vaccines to protect the population from the disease and limit the spread of the virus. An inactivated, whole virus vaccine candidate of SARS-CoV-2 has been developed by Wuhan Institute of Biological Products and Wuhan Institute of Virology. The low toxicity, immunogenicity, and immune persistence were investigated in preclinical studies using seven different species of animals. The results showed that the vaccine candidate was well tolerated and stimulated high levels of specific IgG and neutralizing antibodies. Low or no toxicity in three species of animals was also demonstrated in preclinical study of the vaccine candidate. Biochemical analysis of structural proteins and purity analysis were performed. The inactivated, whole virion vaccine was characterized with safe double-inactivation, no use of DNases and high purity. Dosages, boosting times, adjuvants, and immunization schedules were shown to be important for stimulating a strong humoral immune response in animals tested. Preliminary observation in ongoing phase I and II clinical trials of the vaccine candidate in Wuzhi County, Henan Province, showed that the vaccine is well tolerant. The results were characterized by very low proportion and low degree of side effects, high levels of neutralizing antibodies, and seroconversion. These results consistent with the results obtained from preclinical data on the safety.


Subject(s)
COVID-19 Vaccines/immunology , SARS-CoV-2 , Animals , Antibodies, Viral , COVID-19 Vaccines/adverse effects , Female , Immunity, Humoral , Male , Vaccines, Inactivated/adverse effects , Vaccines, Inactivated/immunology
8.
JAMA ; 324(10): 951-960, 2020 09 08.
Article in English | MEDLINE | ID: covidwho-911581

ABSTRACT

Importance: A vaccine against coronavirus disease 2019 (COVID-19) is urgently needed. Objective: To evaluate the safety and immunogenicity of an investigational inactivated whole-virus COVID-19 vaccine in China. Interventions: In the phase 1 trial, 96 participants were assigned to 1 of the 3 dose groups (2.5, 5, and 10 µg/dose) and an aluminum hydroxide (alum) adjuvant-only group (n = 24 in each group), and received 3 intramuscular injections at days 0, 28, and 56. In the phase 2 trial, 224 adults were randomized to 5 µg/dose in 2 schedule groups (injections on days 0 and 14 [n = 84] vs alum only [n = 28], and days 0 and 21 [n = 84] vs alum only [n = 28]). Design, Setting, and Participants: Interim analysis of ongoing randomized, double-blind, placebo-controlled, phase 1 and 2 clinical trials to assess an inactivated COVID-19 vaccine. The trials were conducted in Henan Province, China, among 96 (phase 1) and 224 (phase 2) healthy adults aged between 18 and 59 years. Study enrollment began on April 12, 2020. The interim analysis was conducted on June 16, 2020, and updated on July 27, 2020. Main Outcomes and Measures: The primary safety outcome was the combined adverse reactions 7 days after each injection, and the primary immunogenicity outcome was neutralizing antibody response 14 days after the whole-course vaccination, which was measured by a 50% plaque reduction neutralization test against live severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Results: Among 320 patients who were randomized (mean age, 42.8 years; 200 women [62.5%]), all completed the trial up to 28 days after the whole-course vaccination. The 7-day adverse reactions occurred in 3 (12.5%), 5 (20.8%), 4 (16.7%), and 6 (25.0%) patients in the alum only, low-dose, medium-dose, and high-dose groups, respectively, in the phase 1 trial; and in 5 (6.0%) and 4 (14.3%) patients who received injections on days 0 and 14 for vaccine and alum only, and 16 (19.0%) and 5 (17.9%) patients who received injections on days 0 and 21 for vaccine and alum only, respectively, in the phase 2 trial. The most common adverse reaction was injection site pain, followed by fever, which were mild and self-limiting; no serious adverse reactions were noted. The geometric mean titers of neutralizing antibodies in the low-, medium-, and high-dose groups at day 14 after 3 injections were 316 (95% CI, 218-457), 206 (95% CI, 123-343), and 297 (95% CI, 208-424), respectively, in the phase 1 trial, and were 121 (95% CI, 95-154) and 247 (95% CI, 176-345) at day 14 after 2 injections in participants receiving vaccine on days 0 and 14 and on days 0 and 21, respectively, in the phase 2 trial. There were no detectable antibody responses in all alum-only groups. Conclusions and Relevance: In this interim report of the phase 1 and phase 2 trials of an inactivated COVID-19 vaccine, patients had a low rate of adverse reactions and demonstrated immunogenicity; the study is ongoing. Efficacy and longer-term adverse event assessment will require phase 3 trials. Trial Registration: Chinese Clinical Trial Registry Identifier: ChiCTR2000031809.


Subject(s)
Betacoronavirus/immunology , Coronavirus Infections/prevention & control , Immunogenicity, Vaccine , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Viral Vaccines/immunology , Adjuvants, Immunologic/administration & dosage , Adjuvants, Immunologic/adverse effects , Adolescent , Adult , Aluminum Hydroxide/administration & dosage , Aluminum Hydroxide/adverse effects , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Betacoronavirus/genetics , COVID-19 , COVID-19 Vaccines , Coronavirus Infections/immunology , Dose-Response Relationship, Immunologic , Double-Blind Method , Female , Humans , Injections, Intramuscular , Male , Pneumonia, Viral/immunology , Propiolactone , SARS-CoV-2 , Vaccines, Inactivated/immunology , Viral Vaccines/administration & dosage , Viral Vaccines/adverse effects , Young Adult
9.
Emerg Microbes Infect ; 9(1): 2013-2019, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-739234

ABSTRACT

COVID-19 is a new respiratory illness caused by SARS-CoV-2, and has constituted a global public health emergency. Cat is susceptible to SARS-CoV-2. However, the prevalence of SARS-CoV-2 in cats remains largely unknown. Here, we investigated the infection of SARS-CoV-2 in cats during COVID-19 outbreak in Wuhan by serological detection methods. A cohort of serum samples were collected from cats in Wuhan, including 102 sampled after COVID-19 outbreak, and 39 prior to the outbreak. Fifteen sera collected after the outbreak were positive for the receptor binding domain (RBD) of SARS-CoV-2 by indirect enzyme linked immunosorbent assay (ELISA). Among them, 11 had SARS-CoV-2 neutralizing antibodies with a titer ranging from 1/20 to 1/1080. No serological cross-reactivity was detected between SARS-CoV-2 and type I or II feline infectious peritonitis virus (FIPV). In addition, we continuously monitored serum antibody dynamics of two positive cats every 10 days over 130 days. Their serum antibodies reached the peak at 10 days after first sampling, and declined to the limit of detection within 110 days. Our data demonstrated that SARS-CoV-2 has infected cats in Wuhan during the outbreak and described serum antibody dynamics in cats, providing an important reference for clinical treatment and prevention of COVID-19.


Subject(s)
Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Betacoronavirus/immunology , Coronavirus Infections/veterinary , Pandemics/veterinary , Pneumonia, Viral/veterinary , Animals , COVID-19 , Cats , China , Coronavirus Infections/epidemiology , Coronavirus Nucleocapsid Proteins , Coronavirus, Feline/immunology , Cross Reactions/immunology , Enzyme-Linked Immunosorbent Assay/methods , Immunoglobulin G/blood , Nucleocapsid Proteins/immunology , Phosphoproteins , Pneumonia, Viral/epidemiology , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/immunology
10.
Cell Res ; 30(8): 670-677, 2020 08.
Article in English | MEDLINE | ID: covidwho-637104

ABSTRACT

The 2019 novel coronavirus (SARS-CoV-2) outbreak is a major challenge for public health. SARS-CoV-2 infection in human has a broad clinical spectrum ranging from mild to severe cases, with a mortality rate of ~6.4% worldwide (based on World Health Organization daily situation report). However, the dynamics of viral infection, replication and shedding are poorly understood. Here, we show that Rhesus macaques are susceptible to the infection by SARS-CoV-2. After intratracheal inoculation, the first peak of viral RNA was observed in oropharyngeal swabs one day post infection (1 d.p.i.), mainly from the input of the inoculation, while the second peak occurred at 5 d.p.i., which reflected on-site replication in the respiratory tract. Histopathological observation shows that SARS-CoV-2 infection can cause interstitial pneumonia in animals, characterized by hyperemia and edema, and infiltration of monocytes and lymphocytes in alveoli. We also identified SARS-CoV-2 RNA in respiratory tract tissues, including trachea, bronchus and lung; and viruses were also re-isolated from oropharyngeal swabs, bronchus and lung, respectively. Furthermore, we demonstrated that neutralizing antibodies generated from the primary infection could protect the Rhesus macaques from a second-round challenge by SARS-CoV-2. The non-human primate model that we established here provides a valuable platform to study SARS-CoV-2 pathogenesis and to evaluate candidate vaccines and therapeutics.


Subject(s)
Betacoronavirus/genetics , Betacoronavirus/immunology , Coronavirus Infections/pathology , Disease Models, Animal , Macaca mulatta/virology , Pneumonia, Viral/pathology , Animals , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/immunology , Betacoronavirus/isolation & purification , COVID-19 , Coronavirus Infections/blood , Coronavirus Infections/diagnostic imaging , Coronavirus Infections/virology , Female , Immunohistochemistry , Male , Pandemics , Pneumonia, Viral/blood , Pneumonia, Viral/diagnostic imaging , Pneumonia, Viral/virology , RNA, Viral/genetics , Radiography, Thoracic , Real-Time Polymerase Chain Reaction , SARS-CoV-2 , Viral Load , Virus Replication
11.
Proc Natl Acad Sci U S A ; 117(17): 9490-9496, 2020 04 28.
Article in English | MEDLINE | ID: covidwho-38297

ABSTRACT

Currently, there are no approved specific antiviral agents for novel coronavirus disease 2019 (COVID-19). In this study, 10 severe patients confirmed by real-time viral RNA test were enrolled prospectively. One dose of 200 mL of convalescent plasma (CP) derived from recently recovered donors with the neutralizing antibody titers above 1:640 was transfused to the patients as an addition to maximal supportive care and antiviral agents. The primary endpoint was the safety of CP transfusion. The second endpoints were the improvement of clinical symptoms and laboratory parameters within 3 d after CP transfusion. The median time from onset of illness to CP transfusion was 16.5 d. After CP transfusion, the level of neutralizing antibody increased rapidly up to 1:640 in five cases, while that of the other four cases maintained at a high level (1:640). The clinical symptoms were significantly improved along with increase of oxyhemoglobin saturation within 3 d. Several parameters tended to improve as compared to pretransfusion, including increased lymphocyte counts (0.65 × 109/L vs. 0.76 × 109/L) and decreased C-reactive protein (55.98 mg/L vs. 18.13 mg/L). Radiological examinations showed varying degrees of absorption of lung lesions within 7 d. The viral load was undetectable after transfusion in seven patients who had previous viremia. No severe adverse effects were observed. This study showed CP therapy was well tolerated and could potentially improve the clinical outcomes through neutralizing viremia in severe COVID-19 cases. The optimal dose and time point, as well as the clinical benefit of CP therapy, needs further investigation in larger well-controlled trials.


Subject(s)
Betacoronavirus , Coronavirus Infections/therapy , Pneumonia, Viral/therapy , Antibodies, Neutralizing/therapeutic use , Antibodies, Viral/therapeutic use , COVID-19 , COVID-19 Testing , Clinical Laboratory Techniques , Coronavirus Infections/diagnosis , Coronavirus Infections/physiopathology , Female , Humans , Immunization, Passive , Male , Middle Aged , Pandemics , Pneumonia, Viral/diagnosis , Pneumonia, Viral/physiopathology , RNA, Viral , SARS-CoV-2 , Viral Load , COVID-19 Serotherapy
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