According to China News, on November 29, Chang Zhaorui, a researcher at the CDC’s Transmission and Prevention Division, said that international and domestic surveillance data confirmed that the pathogenicity and virulence of the Omicron mutant strain and its evolutionary offshoots BA.1, BA.2, and BA.5 series, including BF.7, BQ.1, and recombinant XBB, are significantly weaker compared to mutant strains such as the original strain and delta.
She also said that foreign studies have shown that the Omicron mutant strain causes significantly lower rates of severe disease and death than the previous original strain and the variant of concern.
She quoted foreign studies indicating that this is both a characteristic of Omicron itself and may be related to vaccination and timely intervention for treatment.
According to the Global Times, the pathogenicity of the Omicron variant has decreased geometrically compared to the original strain of the new coronavirus and other mutant strains that have subsequently emerged.
A paper published in Nature earlier this year by a research team from the University of Hong Kong and Hainan Medical College showed that the Omicron B.1.1.529 mutant strain, which appeared in November 2021, had significantly reduced replication capacity in human lung epithelial cells Calu3 and intestinal epithelial cells Caco2.
In mid-November, a paper published in Science Advances by a team of American researchers expressed similar views.
In an interview with the Global Times, Lan Ke, director of the State Key Laboratory of Virology at WOU, said that in vitro infection experiments found that the Omicron mutant strain was significantly less capable of infecting human lung cells (calu-3) than the original strain, with intracellular replication more than 10 times less efficient than the original strain. (China News Network, Global Times)
