Molecular biology tech, Sarah Corcoran, prepares SARS-CoV-2 samples as part of the RNA sequencing process at Ohio State University, where the Omicron variant of coronavirus was recently identified in several samples from Ohio, in Columbus, Ohio, US, December 13, 2021. (Photo: Reuters)

Compared to the earlier Delta variant, Omicron multiplies itself 70 times more quickly in tissues that line airway passages, which may facilitate person-to-person spread, they said. But in lung tissues, Omicron replicates 10 times more slowly than the original version of the coronavirus, which might contribute to less-severe illness.

A formal report of the findings is under peer review for publication and has not been released by the research team.

In a news release issued by Hong Kong University, study leader Dr. Michael Chan Chi-wai said that it is important to note that the severity of disease in humans is not determined only by virus replication but also by each person's immune response to the infection, which sometimes evolves into life-threatening inflammation.