Looking at infected human lungs, researchers in Hong Kong found similar results – Omicron grew quickly in the upper airways, but struggled further down. It’s believed a protein common in the lungs called TMPRSS2, which inadvertently helped previous strains of SARS-CoV-2 infect cells, struggles to grab onto the highly mutated Omicron.
Ravindra Gupta, a virologist at the University of Cambridge, told the Times Omicron has evolved in a way that helps it spread more rapidly, rather than kill its current host.
“It’s all about what happens in the upper airway for it to transmit, right? It’s not really what happens down below in the lungs, where the severe disease stuff happens. So you can understand why the virus has evolved in this way.”
Case numbers vs deaths
After spiking rapidly in early December, daily case numbers in South Africa – where Omicron was first discovered – have plummeted, falling at almost the same heady rate in the past two weeks that they exploded. Deaths only rose minimally – the seven-day average only reaching about one-tenth what it was during the nation’s mid-year outbreak.
While case numbers elsewhere are still growing, deaths aren’t following the pattern set by previous waves. Ireland recorded more cases between Christmas Day and New Year’s Day than it did in all of 2020, yet its seven-day average death toll has remained below 10. The UK is setting new infection records almost every day, yet deaths there have flatlined at around 100 a day – this time last year, the average was over 1200.
So could this be the beginning of the end of the pandemic? Experts expect COVID-19 to eventually become endemic – meaning it’s around, but the number infected is relatively stable and it’s no longer threatening to overwhelm health systems.
But whether that’s an acceptable state of affairs could depend on whether Omicron patients are at risk of developing long COVID. It’s estimated around a third of people who develop COVID-19 continue to suffer symptoms like coughing and fatigue long after they’ve recovered. Just how long it lasts remains unknown – COVID-19 is still a new disease, after all.
“We really want to know (or at least have a reasonable prediction of) how common long COVID is after an Omicron infection,” Dr Blakely wrote in The Age. “To me, at least, I suspect that Omicron will induce long COVID less frequently and less severely. Why? Because it is more an infection of the airways, not the ‘body’.
“But my conjecture is just that – conjecture that needs other experts to weigh in on.”