The omicron variant of Covid-19 replicates 70 times faster in human airways than delta, but infection in the lungs appears to be less severe compared to the original virus strain, according to a study published [recently] by researchers at the University of Hong Kong’s Faculty of Medicine.
Dr. Michael Chan Chi-wai and a team of researchers found that the variant replicates much faster in the bronchus, which connects the windpipe to the lungs, 24 hours after infection. Yet it reproduces more than 10 times slower in the actual human lung tissue, they said.
The study is under peer review.
Omicron’s rapid replication in the airway may explain why it transmits faster than previous variants of the virus, but lower infection in the lungs may indicate that it causes less severe disease, according to the study’s findings.
“It is important to note that the severity of disease in humans is not determined only by virus replication but also by the host immune response to the infection,” Chan said in a statement.
Chan noted that a highly contagious virus like omicron may cause more severe disease and death simply by spreading much faster, even though the lung infection appears not as bad.