ECONOMYNEXT – Transmissibility of the Omicron variant of the COvid 19 virus is higher than the Delta and the original variant, and have the ability to partially escape immunity from vaccines and past infection, a study done by a research team in Hong Kong said.
A study done by researchers from the LKS Faculty of Medicine at The University of Hong Kong including Professor Malik Pieris, has found that the Omicron SARS-CoV-2 infects and multiplies 70 times faster than the Delta variant and original SARS-CoV-2 in human bronchus, which may explain why Omicron may transmit faster between humans than previous variants.
However, the study shows that the Omicron infection in the lung is significantly lower than the original SARS-CoV-2, which may be an indicator of lower disease severity.
“At 24 hours after infection, the Omicron variant replicated around 70 times higher than the Delta variant and the original SARS-CoV-2 virus, however, the Omicron variant replicated less efficiently (more than 10 times lower) in the human lung tissue than the original SARS-CoV-2 virus,” the study said.
The research is currently under peer review for publication.
Michael Chan Chi-wai, Associate Professor, School of Public Health, and Principal Investigator said, the severity of disease in humans is not determined only by virus replication but also by the host immune response to the infection, which may lead to dysregulation of the innate immune system.
He said, by infecting many more people, a very infectious virus may cause more severe disease and death even though the virus itself may be less pathogenic.
“Therefore, taken together with our recent studies showing that the Omicron variant can partially escape immunity from vaccines and past infection, the overall threat from Omicron variant is likely to be very significant.’” Chan said.
The research was conducted by a team led by Dr Michael Chan Chi-wai, Associate Professor, School of Public Health, HKUMed and Principal Investigator, C2i, HKSTP. The research team included Kenrie Hui Pui-yan, Assistant Professor; Professor Malik Peiris, Tam Wah-Ching Professor in Medical Science and Chair Professor of Virology, Professor Leo Poon Lit-man, School of Public Health, HKUMed; and Professor John Nicholls, Clinical Professor, Department of Pathology, HKUMed.
According the World Health Organization, since the last update published on December 7, additional countries across all six WHO Regions have reported confirmed cases of the Omicron variant. As of December14,2021, the Omicron variant has been confirmed in 77 countries.
“Based on current limited evidence Omicron appears to have a growth advantage over Delta. It is spreading faster than the Delta variant in South Africa where Delta circulation was low, but also appears to be spreading more quickly than the Delta variant in countries where the incidence of Delta is high, such as in the United Kingdom,” WHO in its weekly Epidemiology update said.
WHO said, preliminary evidence suggests that there may be a reduction in vaccine efficacy and effectiveness against infection and transmission associated with Omicron, as well as an increased risk of reinfection.(Colombo/ Dec 15/2021)