Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 18 de 18
Filter
1.
Int J Biol Sci ; 18(12): 4648-4657, 2022.
Article in English | MEDLINE | ID: covidwho-1954693

ABSTRACT

Asymptomatic infection with SARS-CoV-2 is a major concern in the control of the COVID-19 pandemic. Many questions concerning asymptomatic infection remain to be answered, for example, what are the differences in infectivity and the immune response between asymptomatic and symptomatic infections? In this study, based on a cohort established by the Wuchang District Health Bureau of Wuhan in the early stage of the COVID-19 pandemic in Wuhan in 2019, we conducted a comprehensive analysis of the clinical, virological, immunological, and epidemiological data of asymptomatic infections. The major findings of this study included: 1) the asymptomatic cohort enrolled this study exhibited low-grade but recurrent activity of viral replication; 2) despite a lack of overt clinical symptoms, asymptomatic infections exhibited ongoing innate and adaptive immune responses; 3) however, the immune response from asymptomatic infections was not activated adequately, which may lead to delayed viral clearance. Given the fragile equilibrium between viral infection and host immunity, and the delayed viral clearance in asymptomatic individuals, close viral monitoring should be scheduled, and therapeutic intervention may be needed.


Subject(s)
COVID-19 , Asymptomatic Infections , Humans , Immunity , Immunity, Innate , Pandemics , SARS-CoV-2
2.
mLife ; n/a(n/a), 2022.
Article in English | Wiley | ID: covidwho-1885423

ABSTRACT

Gut microbiota composition is suggested to associate with coronavirus disease 2019 (COVID-19) severity, but the impact of gut microbiota on health outcomes is largely unclear. We recruited 81 individuals from Wuhan, China, including 13 asymptomatic infection cases (Group A), 24 COVID-19 convalescents with adverse outcomes (Group C), 31 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) re-positive cases (Group D), and 13 non-COVID-19 healthy controls (Group H). The microbial features of Groups A and D were similar and exhibited higher gut microbial diversity and more abundant short-chain fatty acid (SCFA)-producing species than Group C. Group C was enriched with opportunistic pathogens and virulence factors related to adhesion and toxin production. The abundance of SCFA-producing species was negatively correlated, while Escherichia coli was positively correlated with adverse outcomes. All three groups (A, C, and D) were enriched with the mucus-degrading species Akkermansia muciniphila, but decreased with Bacteroides-encoded carbohydrate-active enzymes. The pathways of vitamin B6 metabolic and folate biosynthesis were decreased, while selenocompound metabolism was increased in the three groups. Specifically, the secondary bile acid (BA) metabolic pathway was enriched in Group A. Antibiotic resistance genes were common among the three groups. Conclusively, the gut microbiota was related to the health outcomes of COVID-19. Dietary supplementations (SCFAs, BA, selenium, folate, vitamin B6) may be beneficial to COVID-19 patients.

3.
Front Immunol ; 13: 905431, 2022.
Article in English | MEDLINE | ID: covidwho-1883914

ABSTRACT

The Zika virus (ZIKV) epidemic poses a substantial threat to the public, and the development of safe and effective vaccines is a demanding challenge. In this study, we constructed a kind of self-assembling nanovaccine which confers complete protection against ZIKV infection. The ZIKV envelop protein domain III (zEDIII) was presented on recombinant human heavy chain ferritin (rHF) to form the zEDIII-rHF nanoparticle. Immunization of mice with zEDIII-rHF nanoparticle in the absence of an adjuvant induced robust humoral and cellular immune responses. zEDIII-rHF vaccination conferred complete protection against lethal infection with ZIKV and eliminated pathological symptoms in the brain. Importantly, the zEDIII-rHF nanovaccine induced immune response did not cross-react with dengue virus-2, overcoming the antibody-dependent enhancement (ADE) problem that is a safety concern for ZIKV vaccine development. Our constructed zEDIII-rHF nanovaccine, with superior protective performance and avoidance of ADE, provides an effective and safe vaccine candidate against ZIKV.


Subject(s)
Zika Virus Infection , Zika Virus , Animals , Antibodies, Viral , Antibody-Dependent Enhancement , Immunization , Mice
5.
Chemical science ; 13(4):1119-1129, 2021.
Article in English | EuropePMC | ID: covidwho-1696188

ABSTRACT

Bimolecular fluorescence complementation (BiFC) and its derivative molecular biosensor systems provide effective tools for visualizing biomolecular interactions. The introduction of red and near-infrared fluorescence emission proteins has expanded the spectrum of signal generating modules, enabling BiFC for in vivo imaging. However, the large size of the signal module of BiFC can hinder the interaction between proteins under investigation. In this study, we constructed the near-infrared BiFC and TriFC systems by splitting miRFP670nano, the smallest cyanobacteriochrome-evolved phytochrome available. The miRFP670nano-BiFC sensor system identified and enabled visualization of protein–protein interactions in living cells and live mice, and afforded a faster maturation rate and higher photostability and cellular stability when compared with those of reported near-infrared BiFC systems. We used the miRFP670nano-BiFC sensor system to identify interactions between the nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and cellular stress granule proteins in living cells and found that the N protein downregulated the expression level of granule protein G3BP1. With the advantages of small size and long wavelength emission of the signal module, the proposed molecular biosensor system should be suitable for various applications in cell imaging studies. The smallest near-infrared fluorescence complementation system for imaging protein–protein and RNA–protein interactions in living cells and live mice.

6.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-316036

ABSTRACT

The pseudovirus strategy makes studies of highly pathogenic viruses feasible without the restriction of high-level biosafety facility, thus greatly contributing to virology and being used in research of SARS-CoV-2. Here, we generated a dual-color pseudo-SARS-CoV-2 virus using an HIV-1 pseudovirus production system and the SARS-CoV-2 spike (S) glycoprotein, of which the membrane was labeled with lipophilic dye (DiO) and the genomic RNA-related viral protein R (Vpr) of the viral core were fused with mCherry. With this dual-color labeling strategy, not only the movement of the whole virus but also the fate of the labeled components can be traced. The pseudovirions were applied to track viral entry at a single particle level in four types of the human respiratory cells: nasal epithelial cells (HNEpC), pulmonary alveolar epithelial cells (HPAEpiC), bronchial epithelial cells (BEP-2D), and oral epithelial cells (HOEC). Pseudo-SARS-CoV-2 entered into the host cell and released viral core into the cytoplasm,which clearly indicates that the host entry mainly occurred through endocytosis. The infection efficiency was found to be correlated with the expression of the known receptor of SARS-CoV-2, angiotensin-converting 2 (ACE2) on the host cell surface. We believe that the dual-color fluorescence labeled pseudovirus system created in this study can be a useful tool in SARS-CoV-2/COVID-19 for many purposes.

7.
Chem Sci ; 13(4): 1119-1129, 2022 Jan 26.
Article in English | MEDLINE | ID: covidwho-1627289

ABSTRACT

Bimolecular fluorescence complementation (BiFC) and its derivative molecular biosensor systems provide effective tools for visualizing biomolecular interactions. The introduction of red and near-infrared fluorescence emission proteins has expanded the spectrum of signal generating modules, enabling BiFC for in vivo imaging. However, the large size of the signal module of BiFC can hinder the interaction between proteins under investigation. In this study, we constructed the near-infrared BiFC and TriFC systems by splitting miRFP670nano, the smallest cyanobacteriochrome-evolved phytochrome available. The miRFP670nano-BiFC sensor system identified and enabled visualization of protein-protein interactions in living cells and live mice, and afforded a faster maturation rate and higher photostability and cellular stability when compared with those of reported near-infrared BiFC systems. We used the miRFP670nano-BiFC sensor system to identify interactions between the nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and cellular stress granule proteins in living cells and found that the N protein downregulated the expression level of granule protein G3BP1. With the advantages of small size and long wavelength emission of the signal module, the proposed molecular biosensor system should be suitable for various applications in cell imaging studies.

8.
Int J Biol Sci ; 17(14): 3889-3897, 2021.
Article in English | MEDLINE | ID: covidwho-1438863

ABSTRACT

Intraviral protein-protein interactions (PPIs) of SARS-CoV-2 in host cells may provide useful information for deep understanding of virology of SARS-CoV-2. In this study, 22 of 55 interactions of the structural and accessory proteins of SARS-CoV-2 were identified by biomolecular fluorescence complementation (BiFC) assay. The nucleocapsid (N) protein was found to have the most interactions among the structural and accessory proteins of SARS-CoV-2, and also specifically interacted with the putative packaging signal (PS) of SARS-CoV-2. We also demonstrated that the PS core containing PS576 RNA bears a functional PS, important for the assembly of the viral RNA into virus like particles (VLPs), and the packaging of SARS-CoV-2 RNA was N dependent.


Subject(s)
Coronavirus Nucleocapsid Proteins/metabolism , SARS-CoV-2/metabolism , Virus Assembly , HEK293 Cells , Humans , Phosphoproteins/metabolism , Protein Interaction Maps
9.
Biochem Biophys Res Commun ; 579: 69-75, 2021 11 19.
Article in English | MEDLINE | ID: covidwho-1432975

ABSTRACT

N-glycosylation plays an important role in the pathogenesis of viral infections. However, the role of SARS-CoV-2 RBD N-glycosylation in viral entry remains elusive. In this study, we expressed and purified N331 and N343 N-glycosite mutants of SARS-CoV-2 RBD. We found that de-glycosylation at N331 and N343 drastically reduces the RBD binding to ACE2. More importantly, based on qualitative and quantitative virology research methods, we show that the mutation of RBD N-glycosites interfered with SARS-CoV-2 internalization rather than attachment potentially by decreasing RBD binding to the receptors. Also, the double N-glycosites mutant (N331 + N343) showed significantly increased sensitivity against the designated RBD neutralizing antibodies. Taken together, these results suggest that N-glycosylation of SARS-CoV-2 RBD is not only critical for viral internalization into respiratory epithelial cells but also shields the virus from neutralization. It may provide new insights into the biological process of early-stage SARS-CoV-2 infection with potential therapeutic implications.


Subject(s)
Polysaccharides/metabolism , Pulmonary Alveoli/cytology , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/metabolism , Virus Internalization , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Antibodies, Neutralizing , Binding Sites , COVID-19/metabolism , COVID-19/virology , Cell Line , Epithelial Cells , Glycosylation , Host-Pathogen Interactions/physiology , Humans , Mutation , Polysaccharides/chemistry , Pulmonary Alveoli/virology , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Virus Attachment
10.
Front Immunol ; 12: 701295, 2021.
Article in English | MEDLINE | ID: covidwho-1359190

ABSTRACT

The current pandemic of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has already become a global threat to the human population. Infection with SARS-CoV-2 leads to a wide spectrum of clinical manifestations. Ocular abnormalities have been reported in association with COVID-19, but the nature of the impairments was not specified. Here, we report a case of a female patient diagnosed with glaucoma on re-hospitalization for ocular complications two months after being discharged from the hospital upon recovery from COVID-19. Meanwhile, the patient was found re-positive for SARS-CoV-2 in the upper respiratory tract. The infection was also diagnosed in the aqueous humor through immunostaining with antibodies against the N protein and S protein of SARS-CoV-2. Considering the eye is an immune-privileged site, we speculate that SARS-CoV-2 survived in the eye and resulted in the patient testing re-positive for SARS-CoV-2.


Subject(s)
Aqueous Humor/virology , COVID-19/pathology , Glaucoma/pathology , Reinfection/pathology , Aged , COVID-19/complications , Eye/pathology , Eye/virology , Female , Glaucoma/complications , Humans , SARS-CoV-2/isolation & purification
12.
ACS Appl Mater Interfaces ; 13(21): 24477-24486, 2021 Jun 02.
Article in English | MEDLINE | ID: covidwho-1219585

ABSTRACT

The pseudovirus strategy makes studies of highly pathogenic viruses feasible without the restriction of high-level biosafety facility, thus greatly contributing to virology and is used in the research studies of SARS-CoV-2. Here, we generated a dual-color pseudo-SARS-CoV-2 virus using a human immunodeficiency virus-1 pseudovirus production system and the SARS-CoV-2 spike (S) glycoprotein, of which the membrane was labeled with a lipophilic dye (DiO) and the genomic RNA-related viral protein R (Vpr) of the viral core was fused with mCherry. With this dual-color labeling strategy, not only the movement of the whole virus but also the fate of the labeled components can be traced. The pseudovirions were applied to track the viral entry at a single-particle level in four types of the human respiratory cells: nasal epithelial cells (HNEpC), pulmonary alveolar epithelial cells (HPAEpiC), bronchial epithelial cells (BEP-2D), and oral epithelial cells (HOEC). Pseudo-SARS-CoV-2 entered into the host cell and released the viral core into the cytoplasm, which clearly indicates that the host entry mainly occurred through endocytosis. The infection efficiency was found to be correlated with the expression of the known receptor of SARS-CoV-2, angiotensin-converting 2 (ACE2) on the host cell surface. We believe that the dual-color fluorescently labeled pseudovirus system created in this study can be applied as a useful tool for many purposes in SARS-CoV-2/COVID-19.


Subject(s)
Fluorescent Dyes/chemistry , Pulmonary Alveoli/virology , SARS-CoV-2/physiology , Virus Internalization , Angiotensin-Converting Enzyme 2/metabolism , Endocytosis , Epithelial Cells/virology , Fluorescence , HEK293 Cells , HIV-1/genetics , Humans , Nasal Mucosa/virology , SARS-CoV-2/genetics , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/metabolism
13.
Int J Biol Sci ; 17(6): 1574-1580, 2021.
Article in English | MEDLINE | ID: covidwho-1206435

ABSTRACT

The ongoing coronavirus disease 2019 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has posed a serious threat to global public health and social stability. There is an urgent need for understanding the nature and infection mechanism of the virus. Owing to its high infectivity and pathogenicity and lack of effective treatments, live SARS-CoV-2 has to be handled in biosafety level 3 laboratories, which has impeded research into SARS-CoV-2 and the development of vaccines and therapeutics. Pseudotyped viruses that lack certain gene sequences of the virulent virus are safer and can be investigated in biosafety level 2 laboratories, providing a useful virological tool for the study of SARS-CoV-2. In this review, we will discuss the construction of SARS-CoV-2 pseudoviruses based on different packaging systems, current applications, limitations, and further explorations.


Subject(s)
COVID-19/virology , SARS-CoV-2/physiology , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Humans , SARS-CoV-2/immunology , Viral Genome Packaging
14.
Emerg Microbes Infect ; 10(1): 905-912, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1191602

ABSTRACT

Without an effective vaccine against SARS-CoV-2, the build-up of herd immunity through natural infection has been suggested as a means to control COVID-19. Although population immunity is typically estimated by the serological investigation of recovered patients, humoral immunity in asymptomatic subjects has not been well studied, although they represent a large proportion of all SARS-CoV-2 infection cases. In this study, we conducted a serosurvey of asymptomatic infections among food workers and performed serological and cellular response analyses of asymptomatic subjects in Wuhan, the original epicenter of the COVID-19 outbreak. Our data showed that up to 5.91% of the food workers carried SARS-CoV-2 IgG antibodies asymptomatically; however, in 90.4% of them, the antibody level declined over a 2-week period. IgM and IgG antibodies, including neutralizing antibodies, were significantly lower in asymptomatic subjects than in recovered symptomatic patients with similar disease courses. Furthermore, the asymptomatic subjects showed lymphopenia and a prominent decrease in the B-cell population, as well as a low frequency of antibody-secreting cells and a low cytokine response. These factors probably contributed to the low and unsustained antibody levels in asymptomatic subjects. Our results show that asymptomatic subjects are likely to be vulnerable to SARS-CoV-2 reinfection, and neither the proportion of population immunity nor the breadth of immune responses is sufficient for herd immunity.


Subject(s)
Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Asymptomatic Infections , COVID-19 Serological Testing , COVID-19/immunology , Immunoglobulin G/blood , Immunoglobulin M/blood , Pandemics , SARS-CoV-2/immunology , Antibodies, Neutralizing/biosynthesis , Antibodies, Viral/biosynthesis , B-Lymphocytes , COVID-19/epidemiology , COVID-19 Nucleic Acid Testing , China/epidemiology , Convalescence , Cytokines/blood , Disease Susceptibility , Enzyme-Linked Immunosorbent Assay , Follow-Up Studies , Food Handling , Genome, Viral , Humans , Immunity, Herd , Immunoglobulin G/biosynthesis , Immunoglobulin M/biosynthesis , Lymphocyte Count , Lymphopenia/etiology , Phylogeny , RNA, Viral/blood , Real-Time Polymerase Chain Reaction , SARS-CoV-2/genetics , Seroepidemiologic Studies , Sputum/virology
15.
Nano Today ; 39: 101161, 2021 Aug.
Article in English | MEDLINE | ID: covidwho-1188914

ABSTRACT

The family of coronavirus are named for their crown shape. Encoded by the genetic material inherited from the coronavirus itself, this intrinsic well-known "viral corona" is considered an "inherited corona". After contact with mucosa or the entrance into the host, bare coronaviruses can become covered by a group of dissolved biomolecules to form one or multiple layers of biomolecules. The layers acquired from the surrounding environment are named the "acquired corona". We highlight here the possible role of the acquired corona in the pathogenesis of coronaviruses, which will generate fresh insight into the nature of various coronavirus-host interactions.

16.
Sci Rep ; 11(1): 5975, 2021 03 16.
Article in English | MEDLINE | ID: covidwho-1137818

ABSTRACT

Since the emergence of SARS-CoV-2, numerous studies have been attempting to determine biomarkers, which could rapidly and efficiently predict COVID-19 severity, however there is lack of consensus on a specific one. This retrospective cohort study is a comprehensive analysis of the initial symptoms, comorbidities and laboratory evaluation of patients, diagnosed with COVID-19 in Huoshenshan Hospital, Wuhan, from 4th February to 12th March, 2020. Based on the data collected from 63 severely ill patients from the onset of symptoms till the full recovery or demise, we found not only age (average 70) but also blood indicators as significant risk factors associated with multiple organ failure. The blood indices of all patients showed hepatic, renal, cardiac and hematopoietic dysfunction with imbalanced coagulatory biomarkers. We noticed that the levels of LDH (85%, P < .001), HBDH (76%, P < .001) and CRP (65%, P < .001) were significantly elevated in deceased patients, indicating hepatic impairment. Similarly, increased CK (15%, P = .002), Cre (37%, P = 0.102) and CysC (74%, P = 0.384) indicated renal damage. Cardiac injury was obvious from the significantly elevated level of Myoglobin (52%, P < .01), Troponin-I (65%, P = 0.273) and BNP (50%, P = .787). SARS-CoV-2 disturbs the hemolymphatic system as WBC# (73%, P = .002) and NEUT# (78%, P < .001) were significantly elevated in deceased patients. Likewise, the level of D-dimer (80%, P < .171), PT (87%, P = .031) and TT (57%, P = .053) was elevated, indicating coagulatory imbalances. We identified myoglobin and CRP as specific risk factors related to mortality and highly correlated to organ failure in COVID-19 disease.


Subject(s)
C-Reactive Protein/analysis , COVID-19/pathology , Myoglobin/analysis , Aged , Aged, 80 and over , Biomarkers/blood , COVID-19/complications , COVID-19/mortality , COVID-19/virology , Comorbidity , Female , Humans , Male , Middle Aged , Multiple Organ Failure/etiology , Retrospective Studies , Risk Factors , SARS-CoV-2/isolation & purification , Severity of Illness Index , Survival Analysis , Thorax/diagnostic imaging , Tomography, X-Ray Computed , Troponin I/blood
17.
Virol Sin ; 36(5): 869-878, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1117772

ABSTRACT

Understanding the persistence of antibody in convalescent COVID-19 patients may help to answer the current major concerns such as the risk of reinfection, the protection period of vaccination and the possibility of building an active herd immunity. This retrospective cohort study included 172 COVID-19 patients who were hospitalized in Wuhan. A total of 404 serum samples were obtained over six months from hospitalization to convalescence. Antibodies in the specimens were quantitatively analyzed by the capture chemiluminescence immunoassays (CLIA). All patients were positive for the anti-SARS-CoV-2 IgM/IgG at the onset of COVID-19 symptoms, and the IgG antibody persisted in all the patients during the convalescence. However, only approximately 25% of patients can detect the IgM antibodies, IgM against N protein (N-IgM) and receptor binding domain of S protein (RBD-IgM) at the 27th week. The titers of IgM, N-IgM and RBD-IgM reduced to 16.7%, 17.6% and 15.2% of their peak values respectively. In contrast, the titers of IgG, N-IgG and RBD-IgG peaked at 4-5th week and reduced to 85.9%, 62.6% and 87.2% of their peak values respectively at the end of observation. Dynamic behavior of antibodies and their correlation in age, gender and severity groups were investigated. In general, the COVID-19 antibody was sustained at high levels for over six months in most of the convalescent patients. Only a few patients with antibody reducing to an undetectable level which needs further attention. The humoral immune response against SARS-CoV-2 infection in COVID-19 patients exhibits a typical dynamic of acquired immunity.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Viral , Convalescence , Hospitalization , Humans , Immunity, Humoral , Retrospective Studies , Spike Glycoprotein, Coronavirus
18.
Anal Chem ; 92(15): 10196-10209, 2020 08 04.
Article in English | MEDLINE | ID: covidwho-612210

ABSTRACT

Molecular diagnosis of COVID-19 primarily relies on the detection of RNA of the SARS-CoV-2 virus, the causative infectious agent of the pandemic. Reverse transcription polymerase chain reaction (RT-PCR) enables sensitive detection of specific sequences of genes that encode the RNA dependent RNA polymerase (RdRP), nucleocapsid (N), envelope (E), and spike (S) proteins of the virus. Although RT-PCR tests have been widely used and many alternative assays have been developed, the current testing capacity and availability cannot meet the unprecedented global demands for rapid, reliable, and widely accessible molecular diagnosis. Challenges remain throughout the entire analytical process, from the collection and treatment of specimens to the amplification and detection of viral RNA and the validation of clinical sensitivity and specificity. We highlight the main issues surrounding molecular diagnosis of COVID-19, including false negatives from the detection of viral RNA, temporal variations of viral loads, selection and treatment of specimens, and limiting factors in detecting viral proteins. We discuss critical research needs, such as improvements in RT-PCR, development of alternative nucleic acid amplification techniques, incorporating CRISPR technology for point-of-care (POC) applications, validation of POC tests, and sequencing of viral RNA and its mutations. Improved assays are also needed for environmental surveillance or wastewater-based epidemiology, which gauges infection on the community level through analyses of viral components in the community's wastewater. Public health surveillance benefits from large-scale analyses of antibodies in serum, although the current serological tests do not quantify neutralizing antibodies. Further advances in analytical technology and research through multidisciplinary collaboration will contribute to the development of mitigation strategies, therapeutics, and vaccines. Lessons learned from molecular diagnosis of COVID-19 are valuable for better preparedness in response to other infectious diseases.


Subject(s)
Betacoronavirus/isolation & purification , Coronavirus Infections/diagnosis , Pneumonia, Viral/diagnosis , RNA, Viral/analysis , Betacoronavirus/chemistry , COVID-19 , COVID-19 Testing , CRISPR-Cas Systems , Clinical Laboratory Techniques , False Negative Reactions , High-Throughput Nucleotide Sequencing , Humans , Molecular Diagnostic Techniques , Nucleic Acid Amplification Techniques , Pandemics , Point-of-Care Testing , Reverse Transcriptase Polymerase Chain Reaction , SARS-CoV-2 , Specimen Handling/methods , Viral Load , Viral Proteins/analysis , Waste Water/analysis
SELECTION OF CITATIONS
SEARCH DETAIL