Nurse A nurse examines an X-ray of the lungs of a coronavirus patient on October 13, 2021 at the Casalpalocco Hospital, south of Rome.
Alberto Pizzoli | AFP | Getty Images
The omicron variant of Covid-19 replicates in the human respiratory tract 70 times faster than the delta, but the infection in the lungs appears to be less severe compared to the original virus strain, according to a study published this week by researchers from the Hong Kong faculty. medicine.
Dr. Michael Chan Chi-wai and a team of researchers found that this variant reproduces much faster in the bronchi, which connect the windpipe to the lungs, 24 hours after infection. Nevertheless, according to them, in real human lung tissue, it reproduces more than 10 times slower.
V the study is under peer review… The researchers published their findings before peer review was completed due to the urgency of the pandemic.
The rapid replication of Omicron in the airways may explain why it is transmitted faster than previous variants of the virus, but lower infection in the lungs may indicate it is causing less severe disease, according to research.
“It is important to note that the severity of disease in humans is determined not only by viral replication, but also by the host’s immune response to infection,” Chan said in a statement.
Chan noted that a highly contagious virus like the omicron can cause more serious illness and death by simply spreading much faster, even if the lung infection looks less scary.
“So, together with our recent research showing that the omicron variant may elude vaccine immunity and previous infection in part, the overall threat from the omicron variant is likely to be very significant,” Chan warned.
White House chief medical adviser Dr. Anthony Fauci, citing data from South Africa, said Wednesday that the omicron reduces the protection of Pfizer and BioNTech’s two-dose vaccine against infection by up to 33%, up from 80% before the option appeared.
However, the two-dose vaccine is still 70% effective in preventing hospitalization, Fauci said. Pfizer’s booster dose provides 75% protection against symptomatic diseases, he said.
Pfizer and BioNTech have also published preliminary data from their own laboratory study showing boosters are effective against the omicron, but the original two-dose series was significantly affected by the omicron.
The World Health Organization said on Tuesday that the omicron is spreading faster than any previous Covid variant. Maria Van Kerkhove, WHO technical lead on Covid-19, warns against treating omicron as a mild strain.
“We know that people infected with omicron can have a full spectrum of illnesses, from asymptomatic infection to mild illness to severe illness and death,” Van Kerkhov told the public during a Q&A session.
She warned that increased transmission would lead to more hospitalizations, burdening already weakened health systems.
“If the system is overloaded, people will die,” Van Kerkhove said. “We have to be very careful not to tell the story that this is just a mild disease.”