A Korean research team has proven through experiments that the COVID-19 virus is particularly lethal to the elderly over the age of 65. Previously, it could be read as statistics, but it was only a hypothesis and there was no proof. It is expected to contribute to the development of severe treatment for the elderly.
The Institute for Basic Science (IBS) announced on the 12th that a team led by Choi Young-ki, head of the New Variant Virus Research Center (Chungbuk National University College of Medicine), of the Korea Virus Basic Research Institute, had achieved such a result.
The researchers compared the pathogenicity of ferrets (weasel mammals) infected with Corona 19 virus by dividing them into age groups of 6 months, 1 to 2 years, and 3 years or more. As a result of the analysis, young ferrets did not become a source of transmission due to their low pathogenicity and proliferation. On the other hand, older ferrets had a high proliferation rate and a very high transmission rate. The severity was also high, with a large number of viral RNA-positive cells detected in the lungs and the appearance of severe lung lesions.
Similar results were also obtained when analyzing the gene expression pattern of lung tissue by RNA sequencing. In young ferrets, the expression of genes for tissue regeneration after a rapid immune response was increased. However, in the older group, the expression of inflammatory cytokines increased significantly from the early stage of infection. In addition, the immune cells were overactivated and severe inflammation was induced. Cytokines are signaling substances that control the defense system. When overexpressed, it calls a cytokine storm that attacks even normal cells.
The research team also compared the genomes of a critically ill human patient with an elderly ferret genome and found that type I interferon (a type of cytokine) and M1 macrophage hyperactivity are factors for severe disease in the elderly. It has also been proven that the elderly have a high rate of virus transmission and pathogenicity.
Choi Young-ki, head of the center, said, “We have demonstrated for the first time through experiments that there is a big difference in the pathogenicity and transmission rate of the Corona 19 virus depending on the age of the host.
By Kim Young-jun, staff reporter [email protected]
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