This handout illustration image obtained Feb 27, 2020 courtesy of the National Institutes of Health shows a transmission electron microscopic image that shows SARS-CoV-2. (HANDOUT / NATIONAL INSTITUTES OF HEALTH / AFP)
HONG KONG – The University of Hong Kong announced on Friday that its research team had found a mutant strain of COVID-19 at the early phase of the pandemic with the characteristics of an attenuated vaccine, bringing a major breakthrough in the further development of related vaccines.
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In the study with hamsters, researchers from the State Key Laboratory of Emerging Infectious Diseases of the university found that the mutant strain of SARS-CoV-2 with no basic amino acid motif is almost non-pathogenic to hamsters.
According to the researchers, findings of the study also suggested that the SARS-CoV-2 coronavirus is a cross-species event of infection from animals
Hamsters that have been infected with the mutant virus can completely resist the re-infection of the wild-type virus, suggesting that this non-pathogenic mutant strain of the SARS-CoV-2 has the characteristics of an attenuated vaccine, the study revealed.
The research also found that in human cell culture, the virus with the mutant strain has a reproductive rate even higher than that of the prototype virus, which is of great significance for the preparation of inactivated vaccines from the new coronavirus.
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According to the researchers, findings of the study also suggested that the SARS-CoV-2 coronavirus is a cross-species event of infection from animals.
Chen Honglin, a professor from the university's department of microbiology and also a member of the research team, said the study indicated that the SARS-CoV-2 coronavirus is still in the process of adapting to humans, and more mutant strains will occur in the COVID-19 pandemic.
"At the same time, the mutant virus that loses the basic amino acid of the spike protein has low pathogenicity and higher reproductive ability in cultured cells than the original wild-type virus, and is an ideal strain for use in the production of inactivated vaccine," Chen said.
These findings have recently been published in the science journal Nature Communications.