New research supports the notion that the new variant of the Omicron coronavirus is less likely to damage the lungs. However, all the findings of the six research groups suggest that the variant multiplies more in the throat and causes less serious illness.
A growing body of evidence indicates that the Omicron variant of COVID is more likely to infect the throat than the lungs, which scientists say may explain why the strain appears to be more infectious but less deadly than other versions of the virus. Six studies have shown that Omicron does not damage the lungs of people as badly as the Delta variant of Coronavirus and other previous variants of COVID-19. The research has not yet been peer-reviewed by other scientists, notes The Guardian.
“The result of all the mutations that distinguish Omicron from previous variants is that it may have altered its ability to infect different types of cells,” said Dinan Pillay, professor of virology at University College London. “Basically, it looks more capable of infecting the upper respiratory tract — the cells in the throat. Thus, it will multiply more readily in cells there than in cells deep in the lungs. This is indeed preliminary data, but research is pointing in the same direction. “
If the virus produces more cells in the throat, it makes it more transmissible, which will help explain the rapid spread of Omicron. On the other hand, a virus that infects lung tissue well would be potentially more dangerous but less transmissible.
According to Professor James Stewart, researchers from the Molecular Virology group at the University of Liverpool have published a paper showing that Omicron causes “less serious disease” in mice. The research materials show that mice infected with Omicron lose less weight, have a lower viral load and have less severe pneumonia.
“This is one piece of the puzzle,” says Professor Stewart. “Animal simulations do suggest that the disease is less serious than Delta and the original Wuhan virus. It seems that it passes faster, and animals recover faster, and this is due to the incoming clinical data. The first signs suggest that this is good news, but this is not a signal to let your guard down, because if you are clinically vulnerable, the consequences are still small – there are deaths from Omicron. Not everyone can rip off their masks and have a party. “
Nates’ laboratory at the University of Leuven in Belgium found similar results in Syrian hamsters with a lower viral load in the lungs compared to other options. Prof Johan Nates said it could be because the virus infects humans better than hamsters, or that it was more likely to infect the upper respiratory tract, or that it caused a less severe illness.
Another article, presented in the journal Nature last week by US researchers, also showed that mice with Omicron lost less weight and had a lower viral load. And researchers at the Center for Viral Research at the University of Glasgow have found evidence that Omicron has changed the way it enters the body. Omicron showed a significant ability to evade the immunity of people who received two doses of the vaccine, but the booster vaccine gave a “partial restoration of immunity.”
A lot of new research builds on work from the University of Hong Kong last month that showed fewer omicron infections in the lungs, as well as research by Professor Ravi Gupta of the University of Cambridge, whose team examined blood samples from vaccinated patients. They found that Omicron could bypass vaccination, but was less able to penetrate lung cells.
Recent scientific research comes amid controversy over how best to do home testing. Last week, some scientists suggested that lateral flow tests (LFT) may be more accurate if people take throat swabs as well as nose swabs. Professor Jennifer Rone of University College London says her experience with such tests was negative with nasal swabs but positive with a throat sample.
This appears to be supported by a study from South Africa showing that saliva samples subjected to PCR tests are better than nasal swabs when Omicron is detected.
However, Professor Lawrence Young, a virologist at the University of Warwick, argues that the study was not significant enough to draw conclusions. “This is a small study in non-hospitalized acutely symptomatic patients. On the one hand, it confirms previous research showing that saliva analysis can be useful as a simpler approach to sampling. I don’t think this study is important enough to draw any conclusions about Omicron’s behavior.
The UK Health Safety Agency said there is no indication that rapid tests differ in their ability to detect Omicron or Delta variants, although researchers have continuously monitored the tests: “We are currently seeing a large number of reports of positive device tests with side flow. This means we are detecting tens of thousands of cases that might otherwise go unnoticed. ”
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