PNAS: Hamsters generate immunity against SARS-CoV-2! It is possible to accelerate THE COVID-19 study!

, June 28, 2020 /
PRNewswire/ -- In a COVID-19 hamster model that shows important features of human disease, researchers from the University of Wisconsin-Madison, the University of Tokyo and the Icahn School of Medicine at Mount Sinai, found that pre-infected SARS-CoV-2 virus escants from secondary infections, while recovery seropathy treatments can limit virus replication to the lungsSyrian hamsters are often kept as pets and have played an important role in the study of human infectious diseases for decadesThe new study, led by Yoshihiro Kawaoka, was published recently in the Proceedings of the National Academy of SciencesStudies have shown that they are also a useful small animal model for researchers trying to understand SARS-CoV-2 and evaluate vaccines, treatments and drugs to fight the diseasephoto source: Yoshihiro Kawaoka
"A good model for human influenza and SARS-CoV," said Kawaoka, a professor of virology at the University of Washington's School of Veterinary Medicine and a professor of virology at the University of Tokyo"That's why we decided to use it to study COVID-19We wanted to see if the diseases of these animals were similar to those of humans from beginning to endA study published by scientists at the University of Hong Kong at the end of Marchalso showed that Syrian hamsters were a good model for COVID-19-related studiesIn that study, hamsters lost weight, became deficiated, and developed external symptoms of other diseasesKawaoka's team further expanded this work, demonstrating that low-dose and high-dose viruses can be replicated in the respiratory tracts of young hamsters (1 month old) and adult hamsters (7 to 8 months old) in patient samples collected from the United States and JapanThe virus can also infect the upper and lower respiratory tractsthe team also showed that SARS-CoV-2 can cause serious illness in the lungs of infected animalsThis includes lesions and the appearance of "frosted glass" that is often found in lung scans of human patientsThe scan also showed that an area around the hamster's lung cavity was filled with gas, indicating severe lung damageThe researchers observed the most severe effects within 8 days of infection and improved within 10 days"hamsters infected with SARS-CoV-2 have the same CT imaging characteristics as human COVID-19 disease," said Samantha Loeber, a veterinarian and radiologist at the University of Washington's Center for Veterinary Nursing10 days after infection, the researchers stopped detecting the virus in most hamster organs, but most hamsters had lung damage lasting 14 days, while most hamsters infected with high doses of the virus had lung damage that lasted at least 20 daysoverall, the researchers detected the virus in all respiratory organs and brain samples six days after the hamster became infected, although they also contained part of the olfactory ball -- the organ designed to taste, which may cause the source of the virus in the brain sampleThe initial dose of the virus did not affect the number of viruses eventually found in the hamster organsresearchers also looked for the virus in the kidneys, small intestine, colon or blood, but found nothingto determine whether hamsters produced antibodies to SARS-CoV-2 to protect them from reinfection, the researchers injected some of the same animals with another round of the virus about three weeks after initial infection, but could not detect the virus in their airwaysBut they found the virus in the respiratory tracts of previously uninfected control groups"All animals have antibodies and don't get sick again, suggesting that they have developed protective immunity," said Pete Halfmann, a research professor at theKawaoka USABut we still can't say how long this protection will last"
early April, institutions including the University of Washington School of Medicine and Public Health and the University of Washington School of Health launched aclinical trialto test across the country whether the plasma or serum of recovered COVID-19 patients could be provided to patients with antibodies to help them recover Although recovery plasma has been used for treatment in other disease outbreaks, scientists still have limited knowledge of it as a treatment photo source: Yoshihiro Kawaoka, Masaki Iman and Michiko Ujie
So Kawaoka's team extracted the healing serum from previously ill hamsters and mixed it together They infected the new hamsters with SARS-CoV-2 and then injected them with the antibody-filled serum one or two days after the infection hamsters treated within a day of infection had far lower levels of infectious viruses in their nasal cavity and lungs than those treated with simulated treatment Mice who received serum on day 2 showed less significant benefits, although the levels of the virus in their respiratory organs were still low compared to the control group a recent study published in the journal Science suggests that transferring human antibodies to hamsters may also help protect hamsters from serious diseases infected with SARS-CoV-2 Kawaoka added: "This shows us that restored serum (still being tested in human patients) may be an effective method of treating COVID-19 "
finally, the team also obtained images of the first internal features of the SARS-CoV-2 virus, which helped it replicate or self-replicate in the host cell The researchers say this is worth further study (BioValleyBioon.com) reference: Hamsters develop conservation immunity to COVID-19 and are ar-fod by convalescent sera Masaki Imai et al Syrian hamsters as a small animal model for SARS-CoV-2 infection and , proceedings of the National Academy of Sciences (2020) DOI: 10.1073/pnas.200979117
Thomas F Rogers et al Isolation of the potent SARS-CoV-2 neutraling anti and protection from disease in a animal small model , Sciencebodies (2020) DOI: 10.1126/science.abc7520
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