Hong Kong researchers find early COVID-19 mutant strain with characteristics of attenuated vaccine

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.

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, the virus that causes COVID-19 and loses the basic amino acid motif, is almost non-pathogenic to hamsters.

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.

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.