Health
Related: About this forumCovid: Is There A Limit To How Much Worse Variants Can Get?
- 'Covid: Is there a limit to how much worse variants can get?' BBC News, 6/12/21. - Ed.
It is clear we are now dealing with a virus that spreads far more easily - probably more than twice as easily - as the version that emerged in Wuhan at the end of 2019. The Alpha variant, first identified in Kent, UK, performed a large jump in its ability to transmit. Now Delta, seen first in India, leapt further still. - This is evolution in action. - So are we doomed to a never-ending parade of new and improved variants that get harder and harder to contain?
Or is there a limit to how much worse coronavirus can become? It's worth remembering the journey this virus is on.
It has made the jump from infecting a completely different species - its closest relatives are in bats - to us. It's like you, starting a new job: you're competent, but not the finished article. The first variant was good enough to start a devastating pandemic, but now it's learning on the job. When viruses jump to humans it would be "very rare for them to be a perfect," said Prof Wendy Barclay, a virologist from Imperial College London. "They settle in and then they have a great time." There are examples of viruses, she said, from flu pandemics to Ebola outbreaks, making the jump and then accelerating.
- So how far could it go? The cleanest way of comparing the pure biological spreading power of viruses is to look at their R0 (pronounced R-naught). It's the average number of people each infected person passes a virus on to if nobody were immune and nobody took extra precautions to avoid getting infected. That number was around 2.5 when the pandemic started in Wuhan and could be as high as 8.0 for the Delta variant, according to disease modellers at Imperial.
"This virus has surprised us a lot. It is beyond anything we feared," said Dr Aris Katzourakis, who studies viral evolution at the University of Oxford. "The fact it has happened twice in 18 months, two lineages (Alpha & then Delta) each 50% more transmissible is a phenomenal amount of change." It's "foolish", he thinks, to attempt to put a number on how high it could go, but he can easily see further jumps in transmission over the next couple of years. Other viruses have far higher R0s and the record holder, measles, can cause explosive outbreaks...
Con't... https://www.bbc.com/news/health-57431420
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- Oxygen cylinders in India, where the more transmissible Delta variant was first seen.
Blues Heron
(6,121 posts)yet every article has to mention that the delta variant FIRST FOUND IN INDIA is really bad... lol
appalachiablue
(42,869 posts)for some Americans and more- the 'Red' 'Blue,' 'Yellow' kind.
Or use food, sports, car or truck brands/models for names.
Greek letters and country names are beyond plenty. If they care.