What The Latest Promising Pfizer And Moderna Vaccine Trials Mean

12:05 minutes

This story is part of Science Friday’s coverage on the novel coronavirus, the agent of the disease COVID-19. Listen to experts discuss the spread, outbreak response, and treatment.

a needle with the pfizer logo behind it
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After a long ten months, the moment we’ve been waiting for is almost here. This week, drug companies Moderna and Pfizer both announced that clinical trials on their respective COVID-19 vaccines had concluded, and both were found to be 95% effective against the coronavirus. 

While that may be very welcome good news, it comes in the same week that deaths from the coronavirus surpassed 250,000 in the United States. The Atlantic staff writer Sarah Zhang joins Ira to talk about what we can expect over the coming months as these vaccines roll out—with more still to come. Plus, the prehistoric parasites that likely killed a dinosaur, and a scientific debate is sparked on TikTok. 

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Segment Guests

Sarah Zhang

Sarah Zhang is a staff writer at The Atlantic, based in Washington, D.C..

Segment Transcript

IRA FLATOW: This is Science Friday. I’m Ira Flatow.

After a long 10 months, it’s the moment we have been waiting for, well almost. This week, drug companies Moderna and Pfizer both announced that clinical trials on their respective COVID-19 vaccines had concluded, and both were found to be 95% effective against the coronavirus. And while that may be very welcome good news. The bad news is that they are months away from reaching us, and coronavirus cases are at a record rate here in the US. All of this means that we can see a light at the end of the tunnel, but the tunnel itself is still long and dark.

What can we expect over the coming months as these vaccines roll out with perhaps more still to come? Here to fill us in is Sarah Zhang, staff writer for The Atlantic. Welcome back to Science Friday.

SARAH ZHANG: Good morning, Ira. Good to be here.

IRA FLATOW: Now the last numbers I have were 187,000 new cases, 11.8 million total cases, and 252,000 deaths yesterday. But we finally got some good vaccine news. Tell us where we stand with the two drug trials that reported positive results this week.

SARAH ZHANG: Yeah, I think this is some of the best news we’ve had about COVID amidst, as you say, some still pretty dark numbers. Pfizer and Moderna have both released results that their vaccines are 95% effective. Which is great, it’s actually far more effective than many scientists thought or even dared to hope. So what that means is that if you get this vaccine personally, and you get the two doses, wait the two weeks for the immunity to build up, your chances of getting sick are reduced 95%.

But what’s even more important perhaps, is that it means once enough people get the vaccine we’ll reach what is called herd immunity, which we’re hearing a lot about recently. But it just means that enough people are immune that the virus stopped spreading, and this pandemic ends. That is still many, many months off. But the fact that these vaccines are very effective, means we have to vaccinate fewer people to reach herd immunity. So that’s good news as well.

IRA FLATOW: Now, the vaccines though, are tested under very strict conditions. Can we expect the same kind of results once they get out in the wild, so to speak?

SARAH ZHANG: Yeah, that’s a really great question. As I said, these vaccines require two doses, and they also require it to be stored at frozen temperatures, one of them actually ultra cold temperatures. So you can imagine as these vaccines are being shipped, maybe one batch gets a little bit too warm, maybe some people forget to come back for their second dose or wait a little bit too long. So you might see the effectiveness go down slightly under real world conditions. But it’s great that we’re starting from a baseline of 95% already.

IRA FLATOW: And there have been a large number of people in these trials, which is good news too, right?

SARAH ZHANG: Yeah, exactly. And actually unusually large, because we’re trying to do these trials very fast. One of the things you do when you are doing these trials, is of course, try to figure out how safe the vaccines are. Normally, what you might do is, you just wait a long time. Now we are seeing these trials have tens of thousands of people compared to usually just thousands. So we have a pretty good idea. These vaccines, they’re not totally side effect free. You might feel a little not-so-hot for a day or so. But there are no serious events.

IRA FLATOW: Could these vaccines be in competition with each other?

SARAH ZHANG: Well I think over the next couple of months, Pfizer and Moderna said they can collectively supply enough doses for maybe a little bit over 20 million Americans. So I think we’re going to need all of the vaccines we can get over the next few months. One of the things we might see is that these vaccines are very similar but they do have slightly different shipping and storage requirements. So Pfizer’s, in particular, needs to be stored at negative 94 degrees Fahrenheit, which is much, much colder than your average freezer. And a lot of your CVS, or your rural clinic might not have that capacity. So what you might see is maybe Pfizer’s vaccine goes to a large hospital that does have a deep freezer, and Moderna’s vaccine goes to smaller places that don’t quite have the storage requirements.

IRA FLATOW: And there could be other vaccines too that are in the works.

SARAH ZHANG: Yeah exactly. One of the other really exciting things about this data is that a lot of the other vaccines use a very similar strategy, they target what is called the spike protein of the virus. So the fact that these two look pretty good is a case for optimism that more are down the line and hopefully they will work out as well.

IRA FLATOW: Now Pfizer said that they’re requesting emergency authorization today. What does that mean?

SARAH ZHANG: So what’s going to happen now, is that the FDA is going to convene a outside group of scientists that are going to meet in, what looks like, early December. They’re going to have a series of public meetings, where they’re going to, very publicly, put all this data through the paces, and scrutinize it and make sure it says everything that the company says that it’s saying. So we’re going to have this really public discussion of how good these vaccines are, and then the FDA gets make a decision. And this is a pretty rigorous process. So by the end of it, I think, if it all works out, we should have pretty good confidence in these vaccines.

IRA FLATOW: That’s great. Let’s move on to other news, some of it not so happy to report. And one is that the Trump administration said that they plan to sell off land in the Arctic National Wildlife Refuge to oil companies, and it will happen just three days before the inauguration. What’s going on here, why are they doing this?

SARAH ZHANG: Yeah, this Is actually a really good question. The administration has put in place this process that– pretty much the earliest day the sale can happen is January 17th, which is three days before the inauguration. Oil and gas is a part of the economy in Alaska. And drilling in this refuge has been a controversy for years. Back in 2017 Alaska’s senator, Lisa Murkowski, had put a provision into the tax bill to open up drilling in the Arctic.

IRA FLATOW: Can they actually get this done though, before Biden becomes president?

SARAH ZHANG: So what needs to happen after these sales go through is, actually the Justice Department and various agencies need to review them. And that’s something that should take a month or two. So once Joe Biden becomes president, it’s very possible that something may come up in that review process. Environmental groups are also likely to bring lawsuits, given that this is a really unusual timeline. So it seems pretty likely that something will probably get thrown up. Can’t know for sure.

IRA FLATOW: But in reality this might not happen for another 10 years, right? The time frame here is that the drilling could take 10 years to start.

SARAH ZHANG: Yeah, that’s right. You can’t just say we’re going to build an oil well, and it gets built the next day, right? So it’s going to take many years for these wells to actually start producing oil. That’s actually one of the other big unknowns. Are oil companies actually going to want to drill? A lot of them have kind of seen the writing on the wall, and are investing in renewable energy instead of oil and gas. And you’ve also seen a lot of big banks in the US actually say they’re not going to fund oil and gas projects in the Arctic region. So there’s still a lot of uncertainty even whether companies want to do it.

IRA FLATOW: As we can hear, Sarah, the garbage men are busy this morning, but let’s move on. Two papers out this week confirmed that the biggest mass extinction, 250 million years ago, was caused by burning fossil fuels. How does that happen?

SARAH ZHANG: So this is called the Great Dying. Which is apt because, what happened is that a bunch of volcanoes, over what is now Siberia, were spewing just tons and tons of magma. Enough to cover what would have been the continental United States in kilometer of magma. So this essentially sterilize– almost sterilized the Earth. But what happened was not just the volcanoes themselves. As they were erupting they were also igniting a lot of oil and gas, and fossil fuels that were underneath the land as well. And so one of the lines of evidence for this is that you see a molecule called coronene, which you only see when fossil fuels burn at really, really high temperatures like in magma.

What happened after that, is that this of course released a lot of carbon dioxide. And that carbon dioxide got absorbed in the oceans, and that turned the oceans really acidic. And another group of scientists found that if you just look at the fossils that are around that time, you see evidence of this acidifying ocean. So this maybe sounds a little bit familiar, right? Burning fossil fuels, carbon dioxide is in the oceans. It’s essentially what is happening right now with man-made climate change.

IRA FLATOW: How does that compare though, to the burning of fossil fuels that humans have done? Do we have a scale, or a range, or a comparison?

SARAH ZHANG: So these volcanoes and the fossil fuel release way, way more carbon than we humans ever have. But that process also happened over a million years, which is a blip in geological time, a long time in fossil time. But if you look at the rate of how much carbon dioxide is being released per year, we’re actually doing it at 10 times what the volcanoes were. Of course, we’re probably not going to be doing this for a million years, but it’s a really unprecedented rate.

IRA FLATOW: There is some silver lining here, in that in the UK, Boris Johnson just announced that the UK plans to go green by 2030. Moving to all electric cars in 10 years. That’s a pretty ambitious plan, isn’t it?

SARAH ZHANG: Yeah, that is pretty ambitious. Though you might remember the last time I was on, we also talked about California was looking to end gas and diesel cars. So this has actually been, I think, a really worldwide phenomenon. We’re moving away from gas powered cars to electric cars. And I think that’s great that we are seeing more worldwide action on this.

IRA FLATOW: OK, now sticking with the ancient world for a bit, some paleontologists unearthed some strange looking dinosaur fossils. Tell us about what they found?

SARAH ZHANG: Yeah, these paleontologists found a dinosaur bone in 2006 in Brazil. And right away it was clear that this bone was unusual, there were these lesions on their surface. And it looked like maybe it was bone cancer, which had actually been found by other paleontologists in other dinosaur bones. Recently, they were able to do a CT scan of the bone. And when they looked inside they found that it wasn’t cancer, but it did seem like the bone had been infected when the dinosaur was alive. And in fact, you actually see parasites. Tiny, less than a millimeter long parasites inside the bone, they found about 70 of them.

IRA FLATOW: Wow. So they’re pretty sure that the parasites were there when it died, it did not enter the bone after it died.

SARAH ZHANG: Yeah, the bone itself wasn’t broken and it had these signs of kind of spongy growths of this bone being infected when the dinosaur was alive. So it definitely seems like it was there when the dinosaur had died, and maybe was part of the cause of how that dinosaur ended up dying.

IRA FLATOW: Finally, I am told there has been some discussion on the social media platform TikTok– this sounds crazy– about people able to smell dead ants. You’ve got to tell me more about this one. I just missed it, I guess.

SARAH ZHANG: That’s right. So this began with a user who made a video saying, wow, did you know that people can’t smell dead ants? And, I don’t know about you Ira, but I’ve actually never smelled a dead ant so–

IRA FLATOW: I’ve never tried. How do you know?

SARAH ZHANG: Me neither. But apparently, to some people and some ants, the smell is very pungent and very obvious. So actually depending on the species of the ant, they can smell anything like blue cheese. There’s another species of ant that releases something called formic acid when it attacks, so when you try to go squash it, it’s going to spray this acid and that can smell like vinegar. There are others that might smell like citrus. So it depends on the species of the ant, it depends on maybe how observant people are, but maybe also individual variation from person to person.

IRA FLATOW: Does TikTok say whether you need a whole pile of dead ants or just one dead ant?

SARAH ZHANG: Some people said it’s just one.


SARAH ZHANG: I know. I think it’s so fascinating. Just over the past few years, with the blue and white dress for example, that you found these phenomenon where you maybe tell one friend, like hey this weird thing, and now we’re finding out lots and lots of people experience it. So it was just funny to see this phenomenon emerge online and scientists maybe finally getting a chance to think and study it.

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

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