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1.
Virol Sin ; 2022 Sep 28.
Article in English | MEDLINE | ID: covidwho-2050059

ABSTRACT

During the two-year pandemic of coronavirus disease 2019 (COVID-19), its causative agent, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been evolving. SARS-CoV-2 Delta, a variant of concern, has become the dominant circulating strain worldwide within just a few months. Here, we performed a comprehensive analysis of a new B.1.617.2 Delta strain (Delta630) compared with the early WIV04 strain (WIV04) in vitro and in vivo, in terms of replication, infectivity, pathogenicity, and transmission in hamsters. When inoculated intranasally, Delta630 led to more pronounced weight loss and more severe disease in hamsters. Moreover, 40% mortality occurred about one week after infection with 104 PFU of Delta630, whereas no deaths occurred even after infection with 105 PFU of WIV04 or other strains belonging to the Delta variant. Moreover, Delta630 outgrew over WIV04 in the competitive aerosol transmission experiment. Taken together, the Delta630 strain showed increased replication ability, pathogenicity, and transmissibility over WIV04 in hamsters. To our knowledge, this is the first SARS-CoV-2 strain that causes death in a hamster model, which could be an asset for the efficacy evaluation of vaccines and antivirals against infections of SARS-CoV-2 Delta strains. The underlying molecular mechanisms of increased virulence and transmission await further analysis.

2.
Zoonoses ; 1(6), 2021.
Article in English | CAB Abstracts | ID: covidwho-2025742

ABSTRACT

COVID-19, a disease caused by SARS-CoV-2 that produces major symptoms of pneumonia, has been a disaster worldwide. The traceability of SARSCoV- 2 and the discovery of susceptible animal species is crucial to halt viral transmission and explore the mechanism of cross-species transmission. We selected 82 representative ACE2 sequences from the 1000 sequences with the closest homology to the hACE2 protein. All selected ACE2 proteins were subjected to homology modeling. Potential natural and intermediate hosts, as well as animal species susceptible to SARS-CoV-2, were analyzed systematically by calculation of the binding free energy of ACE2 protein to the RBD of SARSCoV- 2. Primates, some wild Felidae, civets, goats, spotted hyenas and golden hamsters are susceptible to SARS-CoV-2 and may be potential intermediate hosts, whereas pangolins, birds and reptiles are unlikely to be intermediate hosts. Mice, rats and guinea pig are not susceptible to SARS-CoV-2. Given their possible susceptibility, non-human primates, goats and golden hamsters could potentially be used as experimental models to examine SARS-CoV-2 infection without transgenesis. Herein, possible candidates for the natural and intermediate hosts of SARS-CoV-2 are suggested, to provide guidance for subsequent studies.

3.
J Virol ; 96(18): e0103422, 2022 09 28.
Article in English | MEDLINE | ID: covidwho-2019727

ABSTRACT

The duration of SARS-CoV-2 genomic RNA shedding is much longer than that of infectious SARS-CoV-2 in most COVID-19 patients. It is very important to determine the relationship between test results and infectivity for efficient isolation, contact tracing, and post-isolation. We characterized the duration of viable SARS-CoV-2, viral genomic and subgenomic RNA (gRNA and sgRNA), and rapid antigen test positivity in nasal washes, oropharyngeal swabs, and feces of experimentally infected Syrian hamsters. The duration of viral genomic RNA shedding is longer than that of viral subgenomic RNA, and far longer than those of rapid antigen test (RAgT) and viral culture positivity. The rapid antigen test results were strongly correlated with the viral culture results. The trend of subgenomic RNA is similar to that of genomic RNA, and furthermore, the subgenomic RNA load is highly correlated with the genomic RNA load. IMPORTANCE Our findings highlight the high correlation between rapid antigen test and virus culture results. The rapid antigen test would be an important supplement to real-time reverse transcription-RCR (RT-PCR) in early COVID-19 screening and in shortening the isolation period of COVID-19 patients. Because the subgenomic RNA load can be predicted from the genomic RNA load, measuring sgRNA does not add more benefit to determining infectivity than a threshold determined for gRNA based on viral culture.


Subject(s)
COVID-19 , RNA, Viral , SARS-CoV-2 , Animals , COVID-19/diagnosis , COVID-19/virology , Cricetinae , Feces/virology , Genomics , Humans , Mesocricetus , RNA, Viral/analysis , RNA, Viral/genetics , SARS-CoV-2/genetics , Virus Shedding
4.
Chinese Journal of Nosocomiology ; 32(9):1430-1434, 2022.
Article in English, Chinese | CAB Abstracts | ID: covidwho-2012147

ABSTRACT

Since the outbreak of COVID-19, the opinion that the aerosol plays a key role in the transmission of SARS-CoV-2 has been controversial. The COVID-19 pandemic has continued interpersonal transmission for more than two years, especially after the emergence of Delta and Omicron variants, making the situation of COVID-19 pandemic more severe. The transmission of SARS-COV-2 variants was significantly accelerated and the time of transmission between generations was significantly shortened. Therefore, it has been questioned to attribute the close-range infection to droplet transmission. The point that the aerosol can also has a close-range transmission and may play a dominant role is neglected under the influence of traditional transmission mode of respiratory infectious diseases. A large number of studies have shown that normal breath, talk and cough could release a large number of respiratory aerosol particles, and the virus particles were mainly tiny particles(=5.0 micro m). The biological activity and infectivity of the droplet nuclei have been questioned in the studies on their physicochemical properties. Animal models of ferrets and hamsters showed that SARS-COV-2 could transmit via aerosol. Therefore, the new evidence for the aerosol transmission of SARS-COV-2 was reviewed in the article so as to provide latest evidence-based evidence for prevention and control of COVID-19.

5.
J Infect Dis ; 2022 Jul 01.
Article in English | MEDLINE | ID: covidwho-1978236

ABSTRACT

BACKGROUND: The epidemiological advantage of Omicron variant is evidenced by its rapid spread and the ability to outcompete prior variants. Among Omicron sub-lineages, early outbreaks were dominated by BA.1 while BA.2 has gained dominance since February 2022. The relative pathogenicity and transmissibility of BA.1 and BA.2 have not been fully defined. METHODS: We compared viral loads and clinical signs in Syrian hamsters after infection with BA.1, BA.2, or D614G variant. A competitive transmission model and next generation sequencing were used to compare the relative transmission potential of BA.1 and BA.2. RESULTS: BA.1 and BA.2 caused no apparent clinical signs while D614G caused more than 10% weight loss. Higher viral loads were detected from the nasal washes, nasal turbinate and lungs of BA.1 than BA.2 inoculated hamsters. No aerosol transmission was observed for BA.1 or BA.2 under the experimental condition that D614G transmitted efficiently. BA.1 and BA.2 were able to transmit among hamsters via direct contact; however, BA.1 transmitted more efficiently than BA.2 under the competitive transmission model. No recombination was detected from direct contacts exposed simultaneously to BA.1 and BA.2. CONCLUSIONS: Omicron BA.1 and BA.2 demonstrated attenuated pathogenicity and reduced transmission potential in hamsters when compared to early SARS-CoV-2 strains.

6.
EBioMedicine ; 79: 103997, 2022 May.
Article in English | MEDLINE | ID: covidwho-1977198

ABSTRACT

BACKGROUND: SARS-CoV-2 Omicron variant is rampantly spreading across the globe. We assessed the pathogenicity and immune response generated by BA.1.1 sub-lineage of SARS-CoV-2 [Omicron (R346K) variant] in 5 to 6-week old Syrian hamsters and compared the observations with that of Delta variant infection. METHODS: Virus shedding, organ viral load, lung disease and immune response generated in hamsters were sequentially assessed. FINDINGS: The disease characteristics of the Omicron (R346K) variant were found to be similar to that of the Delta variant infection in hamsters like viral replication in the respiratory tract and interstitial pneumonia. The Omicron (R346K) infected hamsters demonstrated lesser body weight reduction and viral RNA load in the throat swab and nasal wash samples in comparison to the Delta variant infection. The viral load in the lungs and nasal turbinate samples and the lung disease severity of the Omicron (R346K) infected hamsters were found comparable with that of the Delta variant infected hamsters. Neutralizing antibody response against Omicron (R346K) variant was detected from day 5 and the cross-neutralization titre of the sera against other variants showed severe reduction ie., 7 fold reduction against Alpha and no titers against B.1, Beta and Delta. INTERPRETATION: This preliminary data shows that Omicron (R346K) variant infection can produce moderate to severe lung disease similar to that of the Delta variant and the neutralizing antibodies produced in response to Omicron (R346K) variant infection shows poor neutralizing ability against other co-circulating SARS-CoV-2 variants like Delta which necessitates caution as it may lead to increased cases of reinfection. FUNDING: This study was supported by Indian Council of Medical Research as an intramural grant (COVID-19) to ICMR-National Institute of Virology, Pune.


Subject(s)
COVID-19 , SARS-CoV-2 , Animals , Antibodies, Neutralizing , Cricetinae , Humans , India , Mesocricetus , Virulence
7.
Viruses ; 14(8)2022 07 23.
Article in English | MEDLINE | ID: covidwho-1957457

ABSTRACT

Reinfection risk is a great concern with regard to the COVID-19 pandemic because a large proportion of the population has recovered from an initial infection, and previous reports found that primary exposure to SARS-CoV-2 protects against reinfection in rhesus macaques without viral presence and pathological injury; however, a high possibility for reinfection at the current stage of the pandemic has been proven. We found the reinfection of SARS-CoV-2 in Syrian hamsters with continuous viral shedding in the upper respiratory tracts and few injuries in the lung, and nasal mucosa was exploited by SARS-CoV-2 for replication and shedding during reinfection; meanwhile, no viral replication or enhanced damage was observed in the lower respiratory tracts. Consistent with the mild phenotype in the reinfection, increases in mRNA levels in cytokines and chemokines in the nasal mucosa but only slight increases in the lung were found. Notably, the high levels of neutralizing antibodies in serum could not prevent reinfection in hamsters but may play roles in benefitting the lung recovery and symptom relief of COVID-19. In summary, Syrian hamsters could be reinfected by SARS-CoV-2 with mild symptoms but with obvious viral shedding and replication, and both convalescent and vaccinated patients should be wary of the transmission and reinfection of SARS-CoV-2.


Subject(s)
COVID-19 , SARS-CoV-2 , Animals , Cricetinae , Disease Models, Animal , Humans , Macaca mulatta , Mesocricetus , Nasal Mucosa , Pandemics , Reinfection
8.
Vaccines (Basel) ; 10(7)2022 Jul 18.
Article in English | MEDLINE | ID: covidwho-1939063

ABSTRACT

The COVID-19 pandemic emerged in 2020 and has caused an unprecedented burden to all countries in the world. SARS-CoV-2 continues to circulate and antigenically evolve, enabling multiple reinfections. To address the issue of the virus antigenic variability, T cell-based vaccines are being developed, which are directed to more conserved viral epitopes. We used live attenuated influenza vaccine (LAIV) virus vector to generate recombinant influenza viruses expressing various T-cell epitopes of SARS-CoV-2 from either neuraminidase (NA) or non-structural (NS1) genes, via the P2A self-cleavage site. Intranasal immunization of human leukocyte antigen-A*0201 (HLA-A2.1) transgenic mice with these recombinant viruses did not result in significant SARS-CoV-2-specific T-cell responses, due to the immunodominance of NP366 influenza T-cell epitope. However, side-by-side stimulation of peripheral blood mononuclear cells (PBMCs) of COVID-19 convalescents with recombinant viruses and LAIV vector demonstrated activation of memory T cells in samples stimulated with LAIV/SARS-CoV-2, but not LAIV alone. Hamsters immunized with a selected LAIV/SARS-CoV-2 prototype were protected against challenge with influenza virus and a high dose of SARS-CoV-2 of Wuhan and Delta lineages, which was confirmed by reduced weight loss, milder clinical symptoms and less pronounced histopathological signs of SARS-CoV-2 infection in the lungs, compared to LAIV- and mock-immunized animals. Overall, LAIV is a promising platform for the development of a bivalent vaccine against influenza and SARS-CoV-2.

9.
Gut Microbes ; 14(1): 2100200, 2022.
Article in English | MEDLINE | ID: covidwho-1927236

ABSTRACT

Obese patientss with nonalcoholic steatohepatitis (NASH) are particularly prone to developing severe forms of coronavirus disease 19 (COVID-19). The gut-to-lung axis is critical during viral infections of the respiratory tract, and a change in the gut microbiota's composition might have a critical role in disease severity. Here, we investigated the consequences of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on the gut microbiota in the context of obesity and NASH. To this end, we set up a nutritional model of obesity with dyslipidemia and NASH in the golden hamster, a relevant preclinical model of COVID-19. Relative to lean non-NASH controls, obese NASH hamsters develop severe inflammation of the lungs and liver. 16S rRNA gene profiling showed that depending on the diet, SARS-CoV-2 infection induced various changes in the gut microbiota's composition. Changes were more prominent and transient at day 4 post-infection in lean animals, alterations still persisted at day 10 in obese NASH animals. A targeted, quantitative metabolomic analysis revealed changes in the gut microbiota's metabolic output, some of which were diet-specific and regulated over time. Our results showed that specifically diet-associated taxa are correlated with disease parameters. Correlations between infection variables and diet-associated taxa highlighted a number of potentially protective or harmful bacteria in SARS-CoV-2-infected hamsters. In particular, some taxa in obese NASH hamsters (e.g. Blautia and Peptococcus) were associated with pro-inflammatory parameters in both the lungs and the liver. These taxon profiles and their association with specific disease markers suggest that microbial patterns might influence COVID-19 outcomes.


Subject(s)
COVID-19 , Gastrointestinal Microbiome , Non-alcoholic Fatty Liver Disease , Animals , Cricetinae , Non-alcoholic Fatty Liver Disease/microbiology , Obesity/complications , Obesity/microbiology , RNA, Ribosomal, 16S/genetics , SARS-CoV-2
10.
Clin Infect Dis ; 75(1): e76-e81, 2022 08 24.
Article in English | MEDLINE | ID: covidwho-1852993

ABSTRACT

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can infect human and other mammals, including hamsters. Syrian (Mesocricetus auratus) and dwarf (Phodopus sp.) hamsters are susceptible to SARS-CoV-2 infection in the laboratory setting. However, pet shop-related Coronavirus Disease 2019 (COVID-19) outbreaks have not been reported. METHODS: We conducted an investigation of a pet shop-related COVID-19 outbreak due to Delta variant AY.127 involving at least 3 patients in Hong Kong. We tested samples collected from the patients, environment, and hamsters linked to this outbreak and performed whole genome sequencing analysis of the reverse transcription polymerase chain reaction (RT-PCR)-positive samples. RESULTS: The patients included a pet shop keeper (Patient 1), a female customer of the pet shop (Patient 2), and the husband of Patient 2 (Patient 3). Investigation showed that 17.2% (5/29) and 25.5% (13/51) environmental specimens collected from the pet shop and its related warehouse, respectively, tested positive for SARS-CoV-2 RNA by RT-PCR. Among euthanized hamsters randomly collected from the storehouse, 3% (3/100) tested positive for SARS-CoV-2 RNA by RT-PCR and seropositive for anti-SARS-CoV-2 antibody by enzyme immunoassay. Whole genome analysis showed that although all genomes from the outbreak belonged to the Delta variant AY.127, there were at least 3 nucleotide differences among the genomes from different patients and the hamster cages. Genomic analysis suggests that multiple strains have emerged within the hamster population, and these different strains have likely transmitted to human either via direct contact or via the environment. CONCLUSIONS: Our study demonstrated probable hamster-to-human transmission of SARS-CoV-2. As pet trading is common around the world, this can represent a route of international spread of this pandemic virus.


Subject(s)
COVID-19 , SARS-CoV-2 , Animals , Cricetinae , Disease Outbreaks , Female , Hong Kong/epidemiology , Humans , Mammals , RNA, Viral/genetics , SARS-CoV-2/genetics
11.
Acta Microbiologica Sinica ; 2:672-685, 2022.
Article in Chinese | CAB Abstracts | ID: covidwho-1841702

ABSTRACT

[Objective] To explore whether porcine deltacoronavirus (PDCoV) can infect and proliferate in different animal species-derived cell lines. [Methods] The Sichuan isolate CHN-SC2015of PDCoV was inoculated in twelve cell lines derived from hamster,poultry,monkey, human and swine. After at least five blindly passages in each cell line, the virus was identified by RT-PCR,RT-q PCR, indirect immunofluorescence assay (IFA), and sequencing. [Results] PDCoV caused distinct cytopathic effect (CPE) in Vero,PAM,PK15,ST, and LLC-PK1 cells at the 1st passage (P1) and proliferated to various degrees in PAM,PK15,ST, and LLC-PK1 cells, while the CPE gradually disappeared during subsequent passages in Vero and PAM cells. Except that in the three susceptible cell lines (PK15,LLC-PK1, and ST), the viral copies of the infected cell lines gradually decreased with the increase in passages, and PDCoV could not be detected at P4 or P5 of DEF,Marc-145,HEK-293,ZYM-SIEC02, and PAM cells. PCR results showed that PDCoV could be detected only in CEF and Vero cells at P5. The IFA results showed that PDCoV could infect other cell lines except BHK-21 and ZYM-SIEC02, and specific immunofluorescence was observed in PK15,LLC-PK1, and ST cells at P1,P3, and P9. Therefore, only three cell lines (PK15,LLC-PK1, and ST) were suitable for serial passage, with the virus titers up to 107.11,107.00, and 107.37 TCID50/mL at P9,respectively. After passage in different cell lines,CHN-SC2015 accumulated 14 nucleotide mutations corresponding to 12 amino acid mutations. [Conclusion] This study indicates that PDCoV can infect a variety of cells in vitro, suggesting that it may have the potential of cross-species transmission.

12.
Veterinar ; 59(1):14-23, 2021.
Article in Croatian | CAB Abstracts | ID: covidwho-1837993

ABSTRACT

The first cases of human disease from COVID-19 were recorded in December 2019 in China, from where it spread rapidly around the world. COVID-19, the third emerging coronavirus infection in humans, is caused by the new SARS-CoV-2 virus, which can cause a severe acute respiratory syndrome in some infected individuals. Previous research has revealed the possible animal origin of SARS-CoV-2, with bats considered as natural reservoirs and pangolins as intermediate hosts. To better understand COVID-19 and more successfully control the spread, domestic and wild animals have been infected in experimental conditions. On the other hand, in some species, infections have been recorded in field conditions. Natural infections have been reported in dogs, cats, tigers, lions, and minks, who have been in contact with SARS-CoV-2 positive humans. The reverse transmission of the pathogen, from infected animals to humans, has only been recorded on intensive mink farms. To better understand the pathogenesis of this disease's causative agent, drugs and vaccine trials, some experimental infections were performed on animal models, of which ferrets, rhesus macaques, and hamsters proved to be the most suitable. This article aimed to consolidate known data on the potential origin of SARS-CoV-2, its transmission to humans, infections in animals, and their significance in the epidemiology of COVID-19.

13.
J Immunol Methods ; 505: 113275, 2022 06.
Article in English | MEDLINE | ID: covidwho-1796490

ABSTRACT

Golden Syrian hamsters are increasingly used as a permissive animal model for SARS-CoV-2 virus studies, but the lack of immunological assays and other immunological reagents for hamsters limits its full potential. Herein, we developed an ELISA method to detect antibodies specific to peptides and proteins derived from SARS-CoV-2 virus in immunized golden Syrian hamsters. Under optimized conditions, this assay quantitates antibodies specific for individual viral peptides, peptide pools, and proteins. Hence, this ELISA method allows investigators to quantitatively assess humoral immune responses at the peptide and protein levels and has potential application in the development of peptide-based vaccines to be tested in hamsters.


Subject(s)
COVID-19 , SARS-CoV-2 , Animals , Antibodies, Viral , Cricetinae , Disease Models, Animal , Enzyme-Linked Immunosorbent Assay , Mesocricetus , Peptides
14.
Front Immunol ; 13: 845969, 2022.
Article in English | MEDLINE | ID: covidwho-1775680

ABSTRACT

To control the coronavirus disease 2019 (COVID-19) pandemic and the emergence of different variants of concern (VoCs), novel vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are needed. In this study, we report the potent immunogenicity and efficacy induced in hamsters by a vaccine candidate based on a modified vaccinia virus Ankara (MVA) vector expressing a human codon optimized full-length SARS-CoV-2 spike (S) protein (MVA-S). Immunization with one or two doses of MVA-S elicited high titers of S- and receptor-binding domain (RBD)-binding IgG antibodies and neutralizing antibodies against parental SARS-CoV-2 and VoC alpha, beta, gamma, delta, and omicron. After SARS-CoV-2 challenge, MVA-S-vaccinated hamsters showed a significantly strong reduction of viral RNA and infectious virus in the lungs compared to the MVA-WT control group. Moreover, a marked reduction in lung histopathology was also observed in MVA-S-vaccinated hamsters. These results favor the use of MVA-S as a potential vaccine candidate for SARS-CoV-2 in clinical trials.


Subject(s)
COVID-19 , Animals , Antibodies, Viral , COVID-19/prevention & control , COVID-19 Vaccines , Cricetinae , Humans , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/genetics , Vaccinia virus/genetics
15.
Non-conventional in English | National Technical Information Service, Grey literature | ID: grc-753722

ABSTRACT

A worldwide effort to counter the COVID-19 pandemic has resulted in hundreds of candidate vaccines moving through various stages of research and development, including several vaccines in phase 1, 2 and 3 clinical trials. A relatively small number of these vaccines have been evaluated in SARS-CoV-2 disease models, and fewer in a severe disease model. Here, a SARS-CoV-2 DNA targeting the spike protein and delivered by jet injection, nCoV-S(JET), elicited neutralizing antibodies in hamsters and was protective in both wild-type and transiently immunosuppressed hamster models. This study highlights the DNA vaccine, nCoV-S(JET), we developed has a great potential to move to next stage of preclinical studies, and it also demonstrates that the transiently immunosuppressed Syrian hamsters, which recapitulate severe and prolonged COVID-19 disease, can be used for preclinical evaluation of the protective efficacy of spike-based COVID-19 vaccines.

16.
Tier..rztliche Praxis. Ausgabe K, Kleintiere/Heimtiere ; 49(3):229-235, 2021.
Article in German | CAB Abstracts | ID: covidwho-1744014

ABSTRACT

These proceedings contain 25 papers from the 64th Annual Meeting of the Pathology Section of the German Veterinary Medical Association. Topics include tumour infiltrating lymphocytes in mammary carcinomas in domestic rabbits;what decides good or bad? - global gene expression analysis of the adenoma of the hepatoid perianal glands and adenocarcinoma the canine apocrine anal sac glands;the canine cutaneous histiocytoma - boring or perspective in immuno-oncology?;impact of antibiotic pretreatment on ventilator-induced lung injury: contradiction between histology and transcriptome analysis?;characterization of murine satellite glial cells of the dorsal root ganglia - a unique cell population with potential regenerative capacities;impact of antibiotic pretreatment on ventilator-induced lung injury: contradiction between histology and transcriptome analysis?;primary diffuse leptomeningeals oligodendrogliomatosis in a cat;pathomorphological studies of fibroadnexal dysplasia in dogs;pyogranulomatous inflammation in multiple Organs of a dog with evidence of Corynebacterium tuberculostearicum;ovary tumors in cats - overview of the examination material from 2009-2020 and case report of a recurrent dysgerminoma;atherosclerosis in the dog;spinal neuroenteric cyst in one Saint Bernard;MENX - an endogenous model for pseudohypoxic pheochromocytomas;molecular Level Evolution II: similarities of CLCA2 in sauropsids and mammals;in vivo detection of double-stranded Ribonucleic acid (RNA) as an early detection marker unclear viral infections using the example of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS CoV-2) in experimental infected hamsters;the role of different mast cell subtypes in the context of intestinal carcinogenesis - a species-comparative approach;an underestimated treasure in paraffin - establishment of a global transcriptome analysis canine tumors from FFPE material based on QuantSeq 3' technology;well researched? - an approximation of the role of CLCA1 in joints through usage molecular databases;integration of digitized historical and cytopathology into an open source DICOM database and viewer system;3R 3D: skin model for the study of viral infections;CARD9 signaling promotes hippocampal neurogenesis and cytokine balance in a mouse model of virus-induced encephalitis;neuropathological changes after intranasal infection with Rift Valley fever virus - a murine model for human encephalitis;a T-cell a day keeps Theiler away - the influence non-reactive T-cells on the course of a Theiler virus infection in mice with C57BL/6 background;digitization in pathology - new opportunities and their obstacles;and specific features of satellite glial cells of dog and pig.

17.
Viruses ; 14(3)2022 03 13.
Article in English | MEDLINE | ID: covidwho-1742725

ABSTRACT

The Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) Delta variant has evolved to become the dominant SARS-CoV-2 lineage with multiple sub-lineages and there are also reports of re-infections caused by this variant. We studied the disease characteristics induced by the Delta AY.1 variant and compared it with the Delta and B.1 variants in Syrian hamsters. We also assessed the potential of re-infection by these variants in Coronavirus disease 2019 recovered hamsters 3 months after initial infection. The variants produced disease characterized by high viral load in the respiratory tract and interstitial pneumonia. The Delta AY.1 variant produced mild disease in the hamster model and did not show any evidence of neutralization resistance due to the presence of the K417N mutation, as speculated. Re-infection with a high virus dose of the Delta and B.1 variants 3 months after B.1 variant infection resulted in reduced virus shedding, disease severity and increased neutralizing antibody levels in the re-infected hamsters. The reduction in viral load and lung disease after re-infection with the Delta AY.1 variant was not marked. Upper respiratory tract viral RNA loads remained similar after re-infection in all the groups. The present findings show that prior infection could not produce sterilizing immunity but that it can broaden the neutralizing response and reduce disease severity in case of reinfection.


Subject(s)
COVID-19 , Reinfection , Animals , Cricetinae , Mesocricetus , SARS-CoV-2/genetics , Severity of Illness Index , Trachea
18.
Nature ; 603(7899):13, 2022.
Article in English | ProQuest Central | ID: covidwho-1730272
20.
Clin Infect Dis ; 2021 Sep 23.
Article in English | MEDLINE | ID: covidwho-1700771

ABSTRACT

BACKGROUND: Following the failure of antibody therapies in treating COVID-19 hospitalized patients we investigated the impact of viral replication on the pharmacokinetics (PK) and efficacy of a hyperimmune SARS-CoV-2 Immune Globulin (CoVIG) product in treatment of SARS-CoV-2 infection using the adult Syrian hamster model. METHODS: The CoVIG was manufactured from plasma donors who had recovered from COVID-19. The dose used (400 mg/kg) was based on the dose given in clinical trials to hospitalized COVID-19 patients. Hamsters were given a single dose of CoVIG two days after challenge with the SARS-CoV-2 virus (isolate NY/PV08410/2020), followed by sampling of blood, nasal, tracheal and lung tissues at different time points. The blood samples were assayed for anti-SARS-CoV-2 spike binding and used to calculate PK parameters. Nasal washes, trachea, and lung samples were assayed for viral replication by PCR (sgRNA). RESULTS: CoVIG-treated hamsters showed a reduction in viral replication in the lower respiratory tract, but minimally in the upper respiratory tract, following challenge with SARS-CoV-2. Challenge with SARS-CoV-2 resulted in altered PK parameters proportionate to viral replication, resulting in decreased area under the curve (AUC), accelerated clearance and shorter half-life of CoVIG. CONCLUSIONS: These data indicate that in the presence of actively replicating SARS-CoV-2 virus, PK parameters are altered and should trigger an adjustment in dosing of CoVIG.

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