IRA FLATOW: This is Science Friday. I’m Ira Flatow. Later in the hour, a look at solar power and why it’s the biggest disruptor of fossil fuel energy. But first, it’s been a big week for news on the COVID front with the Pfizer vaccine finally receiving full FDA approval. Moderna is in the process.

And in the wake of that, many organizations are moving toward mandatory vaccinations. It remains to be seen just how much that will move the needle on vaccination numbers and cases and hospitalizations in the US, and big questions remain about the future of the pandemic as well. Joining me now to talk about some of them is Sarah Zhang staff writer for The Atlantic. Welcome back, Sarah.

SARAH ZHANG: Hi, thanks for having me.

IRA FLATOW: Nice to have you as always. Maybe the biggest practical COVID news this week is that final approval of the Pfizer vaccine.

SARAH ZHANG: Yeah, absolutely. I think this is going to be a really important step to getting more people vaccinated. Is it going to convince everyone to get vaccinated? Definitely not. We’ve seen vaccine hesitancy is a really heterogeneous thing. People have different reasons. Maybe some people will be convinced.

But as you said earlier, I think the really big deal is that this is going to empower a lot more employers, a lot more schools to mandate vaccines. We’re already seeing that the military is now going to be mandating the COVID vaccine. Disney employees, people who work for New York City, a bunch of universities, with the Pfizer vaccine getting approved, they’re now making everyone who can get the vaccine get the vaccine.

IRA FLATOW: And increasing vaccination numbers shifts that already complicated risk equation, right? On the one hand, you have more people getting vaccinated, but, on the other hand, you have this Delta variant.

SARAH ZHANG: Yeah, I feel like it’s been really confusing the past several months because, over the previous year, we kind of decided what kind of risk we’re OK with in the middle of a pandemic, and then we have these two big things that have changed. We have vaccines, and we have the Delta variant. And when we put them together, it’s even more confusing thing because what’s going on is that we’re seeing the vaccines are slightly less effective against Delta.

We are seeing more breakthrough infections. We are seeing that people who get breakthrough infections can transmit the virus. But we don’t really have a good sense of exactly how much that is happening. The US hasn’t really been collecting the data. The CDC decided they weren’t going to collect data on mild breakthrough infection, so we’re kind of flying a little bit blind here. We’re relying a lot on what’s going on other countries to try to give us a sense of how much Delta is affecting vaccine efficacy.

I think what’s also so confusing about this moment is that we all sort of have different levels of risk right now. If you’re vaccinated versus you’re unvaccinated, your risk of COVID is very, very different, and we have lots of mixed vaccination households. If you have kids under 12, a lot of times the parents are vaccinated, but the kids can’t be. And this is just such a confusing situation.

IRA FLATOW: Yeah, and, of course, schools are reopening everywhere. And people are wondering, what do I do there? Populations that largely can’t be vaccinated, little kids.

SARAH ZHANG: Yeah, exactly. When you kind of put all the pieces together, we’re having more kids back in school in person this year. We have a more transmissible variant. And we have a lot of places, a lot of states, where you are not allowed to wear masks. It seems pretty likely we’re going to be having a lot of transmission in schools.

Now, experts I’ve talked to have said that, if your school is doing all the things that it should be doing– good ventilation, masking for kids, even regular testing if that’s available, vaccinating all the teachers– if all these things are happening, we don’t really have to worry that much about your kid going to school. The problem is that a lot of places are not doing those things and especially not doing masks, not doing testing.

It’s a really tough time for parents. We’re already seeing that lots of schools are sending thousands of kids to quarantine and isolation. Some schools have even started to go back to remote learning because there’s just so many cases going on. I think the bottom line is, even though the risks of COVID to most kids is pretty low, the risk of Delta disrupting the school year is still really, really high. If you get exposed, if you get sick, you’re still going to end up missing a lot of classes, might have to go back to remote learning. So it’s going to be a bumpy school year.

IRA FLATOW: And what I hear you saying and when I look at it myself, it appears like COVID, in one form or another, is going to be with us for a very long time. It’s not going away any time soon.

SARAH ZHANG: Yeah, I think we have to be prepared to live with this virus for the rest of our lives. Now, that doesn’t mean we’ll be living within a pandemic for the rest of our lives, but this virus looks like it’s going to be what scientists call endemic, which means it’s just going to be another circulating virus. A good comparison is a flu, or even common cold coronaviruses are actually a family. There are actually four coronaviruses that cause the common cold.

We probably had all of those before. We probably had them for us as kids, and the cases are pretty mild. And we’ve actually probably had those four coronaviruses more than once. Immunity wanes really quickly. But we do see that the second time you get infected, the infection is milder, maybe even asymptomatic. And we’re kind of seeing a similar pattern with this coronavirus.

The big problem right now is that there are so many people with no immunity at all. There’s a new virus meeting naive immune systems. Once we get everyone vaccinated or, worse, once everyone is infected and everyone who’s recovered has some immunity, once there’s enough immunity in the population, this pandemic will be over, though the virus itself will keep circulating. It will just be less serious and less dramatic and less disruptive.

IRA FLATOW: That means we have to accept the idea that there will always be cases of it.

SARAH ZHANG: We’re probably never going to zero COVID. We’re going to be living with this virus for a long time.

IRA FLATOW: And does that mean if it’s around all this time and stays around, it’s going to keep changing and mutating well beyond the Delta variant that we have?

SARAH ZHANG: It is. The good news is most scientists I’ve talked to think that the kind of rate of adaptation to this virus is probably going to slow down. So the virus is going to change like the flu virus changes every year. What happens is that, once enough people have some immunity to it, the virus is going to want to try to keep infecting more people. So any variant that is slightly better infecting more people would just become the one that’s dominant. That’s just the way evolution works. We’re kind of in this arms race.

The difference is that, when a lot of people are vaccinated or people have immunity, there will just be less virus circulating. There’s so many cases right now. The virus is replicating so many times. Each time it replicates, it’s kind of like a lottery ticket, where it might be able to find just the right mutations to get better at spreading.

So once a lot of people are vaccinated, there’s just should be less virus around, so that rate of new variants emerging should probably slow down. It’ll probably still happen, but it won’t be like we’re racing so hard to catch up the way we are right now.

IRA FLATOW: Speaking of the virus being all around you, you touched on this briefly. Let’s talk about it just a little bit more, going worldwide. You’ve written about the UK, other countries. Tell us what’s happening there.

SARAH ZHANG: The UK is an interesting comparison because they kind of got hit with the Alpha wave first and also got hit by the Delta wave first. And they also have very high vaccination rates, and they’ve done an especially good job of educating their elderly. So earlier this summer, the UK was seeing really high Delta case rates, but their hospitalizations were a lot lower.

And then sort of counterintuitively, just as they were opening up and they were getting a lot of criticism for opening up during this Delta wave, cases started falling. There are some really interesting reasons why that happened. One is that schools are out. People still aren’t going to work. It’s not exactly totally back to normal in the UK. But it does suggest that Delta is not going to keep spreading uncontrolled if you have a lot of vaccination in your community.

One thing we are seeing different in the UK and the US, though, is that we are seeing, kind of comparably, looking like a lot more hospitalizations. And that’s probably because, in the US, we haven’t done as good as a job vaccinating the elderly and the vulnerable, and we know those are people, if they’re unvaccinated and they get this virus, they’re going to be hospitalized. So in the US, we still have a lot of hospitalizations. In Florida, it’s like the highest number over the entire pandemic.

Other countries, especially a lot of countries that did really well early on the pandemic, like Australia and Vietnam, with kind of really restrictive like zero COVID policies, trying to keep the virus completely out, they’re finding it really hard to sustain that. Vietnam, Australia are getting really high case rates right now. And I think we’re kind of at this inflection point where we’re thinking about, how do we transition from trying to keep this virus out to accepting it’s going to be here?

Australia said, if 80% of the population is vaccinated, we’re going to lift restrictions. But that’s interesting. It’s a hard psychological transition to go from, this is a virus we must keep out, to, OK, we’re going to live with this virus.

IRA FLATOW: So these countries, such as New Zealand, that moved very aggressively to control cases but it’s everywhere, how long can they keep that up?

SARAH ZHANG: That’s a great question. The New Zealand is kind of in the middle of another pretty strict lockdown, a lot stricter than we, in the US, have experienced. This is like, you can’t really leave your house except for certain approved activities. In Australia, where something similar is happening, you’ve seen really big protests even get kind of violent against these restrictions because I think people are fed up. They want to go back to normal life.

I think it’s a good idea to give people a sense of when this is going to end, and probably a certain vaccination threshold, say, 80%– I don’t know the exact number that is right, and it may change, depending on the variant. But giving people some sense of when this will be over in terms of how many people are vaccinated, I think that’s a good psychological motivator.

IRA FLATOW: We’ve always heard the phrase beware of unintended consequences, and it appears that there are unintended consequences here, things that we would not have thought about. For example, we’ve been focused a lot on the stresses the disease is putting on the health care system, but there are other surprising follow-on effects related to oxygen. Tell us how oxygen fits in this whole scene.

SARAH ZHANG: So oxygen is obviously really crucial for COVID patients who are in hospitals and need supplemental oxygen. But oxygen is also used for other things such as rocket launches. This week, SpaceX’s president said that their rocket launch schedule is getting kind of crunched because they’re having trouble getting enough liquid oxygen. Liquid oxygen is propellant that’s used with rocket fuel, and they’re having a hard time getting enough of that.

Another thing that’s happening is that, in Florida, where there’s this huge, huge surge in hospitalizations, oxygen is also used to purify drinking water. Oxygen is used to make ozone. Ozone is basically three oxygen molecules, and that’s used to kind of get some of that nasty stuff out of the water to make it taste a little better. In Florida, they’ve asked people to conserve water because so much of the oxygen has been diverted to hospitals instead. In other cases, they’ve gone from using ozone to purify water to going back to bleach. So the consequences of COVID are kind of rippling through the supply chain.

IRA FLATOW: Oh, with all this heavy news this week, Sarah, have you got any gee-whiz stories we could sort of end with?

SARAH ZHANG: OK, well, here’s one. So paper wasps, their nest turned out to be really brightly fluorescent. So the reason we know this is that a scientist is walking through the woods in Vietnam at night with a black light as you I guess you do if you’re a biologist.

IRA FLATOW: Sure, you just walk through the woods with a black light. [LAUGHS]

SARAH ZHANG: Yeah, exactly. That’s what you do. And he happened to stumble upon this brightly glowing green paper wasp nest, so my colleague, Katherine, who wrote about this this week, paper wasps, they make these nests. They kind of chew up wood fiber, and their nests kind of look like papier mache honeycombs. It’s not the paper itself that’s fluorescent. It turns out to be that the silk that the pupa make is fluorescent, and it glows really brightly green when you have a black light.

IRA FLATOW: Well, that is cool. In nature, glowing things sometimes can be a signal or a marker of something. Do scientists have any idea why these nests glow?

SARAH ZHANG: Yeah, that’s right. Sometimes they are markers. So one hypothesis is maybe these nests glow to help the wasps to navigate. Another hypothesis is maybe the more interesting is that the silk is able to kind of absorb some of the UV rays, so maybe it’s actually kind of a side effect of the protectiveness of the cell, kind of like a natural sunscreen.

IRA FLATOW: Wow, that is pretty cool, and that is a good ender for us, Sarah. Thank you very much for bringing that one up.

SARAH ZHANG: You’re welcome. Thank you for having me.

IRA FLATOW: Sarah Zhang, staff writer for The Atlantic.

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