Today is the second class in our current four class set. We will start class with a casual conversation. Our reading this week is about climate activists. Our listening is an about omicron. Please note this story is from 2015. We will continue with our mini grammar lesson. Writing the sentences on a separate piece of paper by hand is a wonderful way to practice. For today’s mini grammar we will practice ‘used to’ sentences.
Click HERE for the reading
STEVE INSKEEP, HOST:
For close to a year now, omicron and its subvariants have dominated the pandemic. Each time we learn of a new variant, people have to ask, do the vaccines cover this one? What changes now? Scientists are asking how changes in the coronavirus make it such an unpredictable adversary. Here's NPR's health correspondent Rob Stein.
ROB STEIN, BYLINE: Throughout the pandemic, the SARS-CoV-2 virus has been evolving fast, blindsiding the world with one new variant after another. Sally Otto is an evolutionary biologist at the University of British Columbia.
SALLY OTTO: We often have a period of time where we're like, oh, is that it? Are we done? Is this over? And we had that - I don't know if you remember - before delta started to spread. It was like, oh, phew, now this is it. But then delta came on the picture. And then even then there was like, phew, maybe this is the end of the delta wave, and we're home free. And then omicron hit.
STEIN: And omicron was unlike anything before it. The spike protein the virus uses to infect cells bore more mutations than any variants so far, helping it dodge the defenses of people who've been infected or vaccinated. Omicron swept the world with breathtaking speed and drove devastating surges. The World Health Organization hasn't declared a new Greek letter variant since omicron. Instead, omicron has been spinning off a dizzying parade of subvariants with names like BQ.1, BF.7 and XBB. The Centers for Disease Control and Prevention is watching a dozen different omicron subvariants right now, so I started calling scientists to find out if there's any evidence the virus's evolution might be slowing down.
KRISTIAN ANDERSEN: Well, its - the evolution itself has not really slowed down.
EMMA HODCROFT: No, the virus is still having changes at the same rate that it was before.
TREVOR BEDFORD: SARS-CoV-2 is continuing to evolve extremely rapidly. It's still faster than the fastest flu that's circulating.
MANON RAGONNET-CRONIN: There's no evidence that the evolution is slowing down.
MICHAEL WOROBEY: No, it's cooking. It's cooking at a high temperature.
STEIN: That's Kristian Andersen at Scripps Research in California, Emma Hodcroft at the University of Bern in Switzerland, Trevor Bedford at the Fred Hutchinson Cancer Center in Seattle, Manon Ragonnet-Cronin from the University of Chicago, and Michael Worobey at the University of Arizona. They all say what has changed is how the virus is evolving.
RAVI GUPTA: We're entering a sort of interesting and quite distinct phase of virus evolution.
STEIN: Ravi Gupta is at the University of Cambridge in the U.K.
GUPTA: We've been accustomed to seeing waves of totally new variants with very, very different groups of mutations. But now we're seeing something different. We're seeing multiple different strains of virus.
STEIN: That all have one thing in common, according to the University of Bern's Emma Hodcroft.
HODCROFT: The children of omicron - so the many kind of direct children and cousins within the diverse omicron family - those have displaced each other, but that same family has been dominating.
STEIN: By continuing to rapidly evolve into a panoply of subvariants through a very specific kind of evolution. Manon Ragonnet-Cronin from the University of Chicago.
RAGONNET-CRONIN: What's happening right now is that we seem to see for the first time evidence of widescale convergent evolution. We have what people are calling a swarm of omicron viruses, which have different ancestries within omicron, but which have the same set of mutations.
STEIN: Different omicron subvariants have all been independently converging on mutations that give them the same advantage. Here's Sally Otto from the University of British Columbia again.
OTTO: The bad news is that these variants are hitting upon new ways of getting into our bodies and better infecting our cells. So it's like an uninvited guest, and we recognize what they look like, and we don't let them in our house. But then it puts on a costume, and we don't recognize it as well anymore. And we open the door, and it's too late.
STEIN: Too late to keep the virus from continuing to infect massive numbers of people, potentially helping fuel yet another surge and giving the virus lots of chances to reproduce, mutate and evolve even more. Jeremy Kamil is an immunologist at Louisiana State University.
JEREMY KAMIL: This virus is getting a lot of lottery tickets, if you will, and it looks like with these new variants, these mutations are, like, the jackpot.
STEIN: The possible good news is that omicron subvariants could keep evolving this way without suddenly becoming a much bigger threat again. Here's Emma Hodcroft again.
HODCROFT: So I think that the fact that we seem to have stepped out of a phase where we're getting completely new viruses from different parts of the tree sweeping in and dominating - this might be a sign that we're moving towards a more kind of stable future for the virus.
STEIN: But Hodcroft and others warn that's by no means guaranteed. Jeremy Kamil.
KAMIL: I just hope that this is kind of settling into a picture where, yes, it's going to be omicron for a very long time, and we may see little waves, and people might catch COVID, but it's going to be a more predictable event in terms of being something that most people can hopefully shrug off. Is that going to hold? I sure hope so, 'cause if it doesn't, it'll be a pretty scary future.
STEIN: Because the virus is still so new, no one knows how many more tricks it has up its sleeve. Kristian Andersen from Scripps Research.
ANDERSEN: Because we are literally dealing with a completely novel virus here - we are dealing with a virus that we have never encountered starting from Day 1 - we have sort of continued to go back to, like, oh, but it must be like flu, it must be like the common cold coronaviruses. And unfortunately, we just don't know if that's the case.
STEIN: There's no way to rule out, for example, the possibility that a dramatically different variant might emerge yet again, possibly after simmering inside the body of someone with a weak immune system. Michael Worobey is from the University of Arizona.
WOROBEY: I guarantee you that there are people who have been persistently infected with delta and alpha who have some really weird combinations of mutations. And I am fully prepared for a delta-based or alpha-based omicron-like event where one of those zombie viruses that's been cooking away within someone emerges. I think that is going to happen.
STEIN: If it does, this relatively calm phase of the pandemic, dominated by omicron, could come to an abrupt end and dash hopes that the virus would fade into the background.
Rob Stein, NPR News.
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