Omicron spread more in respiratory airways than in lungs, study finds

Concerns about the increased transmittance of the Omicron version have prompted countries around the world to tighten COVID-19 measures. While data about the new type of anxiety is still in the early stages, a new study has found that it infects and spreads 70 times faster in the respiratory airways than earlier COVID-19 strains.

In the study that has not yet been peer-reviewed, researchers at the University of Hong Kong have released one of the first pieces of information on the effect of the Omicron variant on the human respiratory tract. On the other hand, the study also found that the prevalence of omicrons in the patients’ lungs was significantly lower than in the original COVID-19 variant, concluding that this suggests a lower likelihood of severe disease.

The study also showed that omicron infection in the lungs is significantly lower than in the original SARS-CoV-2, which may indicate a lower disease severity.

The researchers used ex-vivo cultures of the respiratory tract to understand why Omicron may differ in transmission and disease severity from other SARS-CoV-2 types.

This method uses lung tissue removed for treatment of the lungs, which is normally discarded, to check for viral diseases of the respiratory tract.

Michael Chan Chi-wai, associate professor at the University of Hong Kong, and his team successfully isolated omicron and compared infection from the 2020 variant with the original SARS-CoV-2 and the delta variant.

The team found that Omicron replicates faster in the human bronchus than the original SARS-CoV-2 virus and the delta version.

The researchers said that 24 hours after infection, the omicron version replicated nearly 70 times more than the delta version and the original SARS-CoV-2 virus.

Omicron replicated less efficiently – 10 times less – in human lung tissue than the original SARS-CoV-2 virus, which could suggest a lower severity of the disease, he said.

Chan said in a statement, “It is important to note that disease severity in humans is determined not only by virus replication, but also by the host immune response to infection, which can lead to dysregulation of the innate immune system.” Is.”

“It is also noted that by infecting many more people, a very contagious virus can cause more severe illness and death, even though the virus itself is less pathogenic,” he explained.

The researchers said that recent studies have shown that Omicron can evade partial immunity from vaccines and previous infections, thus the overall threat is likely to be very significant.