Data from last week showed that a broad immune combination and many mutations had produced a Koronavirus which caused a much worse disease than the previous iteration.
A series of new studies have confirmed the silver layer Omicron variant: even as a number of cases soared for notes, the number of severe cases and hospitalization has not yet. Data, some scientists said, signaling a new chapter of a less worrying pandemic.
“We are now in a completely different phase,” said Monica Gandhi, an immunology at the University of California, San Francisco. “This virus will always be with us, but my hope is that this variant causes so many immunity to extinguish the pandemic.”
Omicron variants found in South Africa more than a month ago, and experts warn that there is still plenty of time for changing situations. But data from last week showed that the combination of widespread immunity and many mutations had produced a virus that caused a much worse disease than the previous iteration.
One study from South Africa found that patients treated at the hospital there during the fourth wave dominated by Omicron from the 73% virus less likely to have severe illnesses than patients dominated by the third wave of Delta. “Data is quite dense now that hospitalization and cases are separated,” said Burger Wendy, an immunology at the University of Cape Town.
Initially, most of the alarm above Omicron was because the variant of the number of mutations, many of which were in protein surge, part of the virus responsible for helping him attack host cells. That mutation, suggested initial data, allows viruses to easily infect not only people who are not vaccinated but also to avoid antibody responses from infections and previous vaccines. But the question still how Omicron will cost after it crosses the first line of defense.
Some factors seem to have made an omicron variant less ferocious, or severe, from the previous Covid-19 wave. One factor is the ability of the virus to infect the lungs. Covid infection usually starts in the nose and spreads to the throat. Light infection does not make it further from the upper respiratory tract, but if the virus reaches the lungs, it is usually when a more severe symptom occurs.
But five separate studies in the past week suggested that the variant did not infect the lungs as easy as the previous variant. In one study, it was released as pre-printed online by a large consortium of Japanese and American scientists, Hamster and mice infected by Omicron suffered far fewer lung damage and tended to die than those infected with the previous variant. Another lesson from Belgium found similar results in Syrian Hamster, which was known to have a very severe disease with the previous viral iteration.
In Hong Kong, scientists studied a small number of samples of lung tissue from patients collected during surgery and found that Omicron grew slower in the sample than other variants.
Burger said this virulence change is likely to be related to how the anatomy of the virus changes.
“I used to use two different lanes to get into cells, and now because all changes in the surge protein, it prefers one of the paths,” he said. “It seems to prefer to infect the upper respiratory tract than the lungs.”
This, said Burgers, can mean a less severe infection, but also more transmitibility when the virus replicates more often in the upper respiratory tract, from which it can spread easier.
While Omicron may be good to avoid antibody attacks, the latest research also shows that it has a much less successful success avoiding the second-line defense of vaccines and previous infections: T cells and B cells.