Your Future COVID-19 Vaccine May Come Through Your Nose

16:45 minutes

a hand squeezes a bottle of vaccine projecting mist spray, on a black background
Early trials of nasal vaccines hold promise. Credit: Shutterstock

The nose knows about COVID-19 infection. It is the entrance to the immune system, after all. The nose’s position as one of our first lines of defense has many experts in favor of developing COVID-19 nasal sprays, with the thought that it may replace the needle jabs we’ve come to expect. 

The development of nasal vaccines comes at a time when many Americans are anxiously awaiting if the government will approve additional COVID-19 boosters. The bivalent boosters have been out for more than six months, and there have been reports the U.S. Food and Drug Administration will recommend an additional dose for some Americans this spring. 

Joining Ira to give us the latest on nasal sprays, boosters, and answering some listener questions is Dr. Akiko Iwasaki, immunobiologist at Yale Medical School in New Haven, Connecticut. 

Further Reading

Segment Guests

Akiko Iwasaki

Akiko Iwasaki is a professor of Immunobiology at the Yale Medical School in New Haven, Connecticut.

Segment Transcript

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

When did you get your last booster shot? I got mine, well, about six months ago. But it appears that I’m in the minority. We’ve gotten very blase about COVID vaccines. So much so that only about 20% of the US population has received an updated bivalent booster shot.

So what’s the current state of our COVID vaccines? Could I get another booster if I wanted to? Here, with the answers to what’s new with boosters, formulas, and recommendations, is Dr. Akiko Iwasaki, professor of immunobiology at Yale Medical School, in New Haven, Connecticut. Welcome back to Science Friday. Good to have you.

AKIKO IWASAKI: Thank you for having me back, Ira.

IRA FLATOW: You’re welcome. OK, let’s jump into the bivalent boosters. Can you remind us what makes these different than the original ones?

AKIKO IWASAKI: So the bivalent booster, as the name suggests, has two types of antigens that are included, the original SARS spike protein as well as the Omicron BA.4, BA.5 spike protein. So these proteins are encoded by mRNA, and they’re mixed together to give a bivalent booster. The idea is to be able to provide antibodies that react against the original SARS-CoV-2 spike as well as the variants of concern that are circulating right now.

IRA FLATOW: Do we know how long this protection from the bivalent boosters lasts?

AKIKO IWASAKI: So typically, if you look at the history of COVID vaccine, the protection lasts for about six to eight months, and then it starts to decline. So my guess would be that the booster will also be waning in its effectiveness over time. So as you mentioned, you are six months from the last booster. Probably it’s time to consider getting another booster shot.

IRA FLATOW: Well, you anticipated my next question. Can I just walk into the drugstore and get a booster? Will they give it to me?

AKIKO IWASAKI: Yeah, I’m not really sure about that. There is no recommendation from the CDC or FDA about the second bivalent booster dose. But I did check on my CVS app, and I was able to get an appointment. My last bivalent booster was about six months ago also. So maybe you can. I don’t know.

IRA FLATOW: OK. Well, I’ll try it and you try it, and we’ll compare notes later, OK?


IRA FLATOW: So should we anticipate that this is the new standard, these bivalents are here to stay, this is our new standard for COVID boosters?

AKIKO IWASAKI: I would think so. For the foreseeable future, the current bivalent boosters are here to stay. If there is an emergence of another variant that has significant mutations in the spike protein that significantly evade these vaccine-based antibody responses, then there may need to be a modification. But right now, I think the current bivalent booster should work well.

IRA FLATOW: OK. Let’s go to questions we got from our audience. We got a question about the booster from Auntie C on Twitter, who asks, when will the vax not make me sick? I did Pfizer as a booster to Moderna and was sick as a dog– in capital letters. I won’t do that again. Still masking and following cleanliness protocols for protection. Any answer to that twitterer?

AKIKO IWASAKI: Oh, that’s a very good question that a lot of people have. The reaction to these vaccines vary greatly between people. Some people just have a little bit of soreness in their arm. Some people develop fever. Some people have a long-lasting reaction to these vaccines.

So yeah, it’s really hard to tell whether the next booster is going to give you the same kind of reactions or not. But I do hear of concerns. And some people are hesitant to get another booster because of the reactions that they got.

IRA FLATOW: Yeah. If you look at what I said– 20% just got a booster– that’s just amazing.


IRA FLATOW: You’d think a lot more people would have gotten one. There has been talk of a flu and COVID combination shot in the future. Does this make sense to you? Does it seem possible?

AKIKO IWASAKI: Yeah, I think it makes a lot of sense in terms of convenience so that people don’t have to remember to make two appointments to get a flu shot and then another one for the COVID shot. So if it becomes an annual vaccine campaign for COVID, you might as well get it the same time as the flu shot. And I think there is effort ongoing to make a combined vaccine shot that you just have to get one shot for the two viruses. That’s hopefully to come in the future.

IRA FLATOW: Yeah. Is there any barrier to doing that?

AKIKO IWASAKI: Yeah. Well, one of the things that I thought of is that, because the COVID vaccines– or the mRNA vaccines– have to be kept in a certain temperature, and you can only use the vaccine, after thawing, within a limited time window, whereas the flu vaccine is kept in a different temperature and it stays for a longer time period, so these kinds of things have to be worked out in terms of stability and how long you can keep these vaccines out of the fridge before you have to deliver it into somebody’s arm. But once those technical details are figured out, it’s theoretically possible to combine these vaccines

IRA FLATOW: OK. A question now from Oren, on Facebook. I would just like to know if there’s another vaccine booster we should be getting as youngish adults, without special risk factors, who have already gotten the covalent booster. I’m pretty sure the answer is no, but getting good info has been frustratingly difficult. Doctor, can we give them good info?

AKIKO IWASAKI: Again, we don’t really have a recommendation from the government yet for how frequently we should be boosting people, especially people who are not at high risk. So if you are a healthy adult who’s gotten boosters and may have gotten the infection along the way, it’s possible that you may not need it quite right now. But maybe there is a full booster coming that is recommended for people, including the general public. And I would just follow that guideline.

IRA FLATOW: Yeah. I should say that there are reports that the FDA will recommend another booster for certain people, like older adults. We’ll hopefully know more in the next few weeks.

President Biden intends to end the National COVID-19 public health emergency. I think the date is May 11th. Will that have any impact, do you think, on vaccines and vaccinations?

AKIKO IWASAKI: Yeah. So because of the emergency provisions, anyone who wanted to get the vaccine could get it for free. After that ends on May 11th, if you don’t have health insurance that covers the vaccine, there may be out-of-pocket payment that one needs to do in order to get these vaccines. I’m not sure exactly how that’s going to be worked out. But there may be an impact like that in terms of accessibility of vaccines to anyone who wants it.

IRA FLATOW: Do you think when the President ends the public health emergency that people are going to say, well, this epidemic is over, I don’t have to worry about COVID transmission anymore?

AKIKO IWASAKI: I think many people are already saying that. And for someone who’s studying COVID and long-COVID, there are definitely issues that are still ongoing. And we are still seeing a significant number of infections and deaths happening from COVID. And of course, very worrisome is the fact that a lot of people are also getting long-COVID.

IRA FLATOW: Yeah, let’s talk about that.


IRA FLATOW: What do we know about at this point how the vaccine protects against long-COVID and what happens with long-COVID?

AKIKO IWASAKI: Right. So there are many studies that are done on this topic. And I think the consensus is that the vaccines do prevent long-COVID to some extent– possibly around 30%. So it’s definitely best to get vaccinated in order to avoid acute and long-COVID. But it’s not perfect. People can certainly get long-COVID after vaccination.

And so that brings me to practicing other types of measures to prevent getting COVID, such as mask wearing and avoiding crowded indoor settings and so on. But I a lot of people are very sick and tired of thinking about these issues. But the virus isn’t done with us. So I still keep doing that myself.

IRA FLATOW: I do, too. I know people with long-COVID, and you don’t want to up your chances of getting long-COVID.

AKIKO IWASAKI: Absolutely not.

IRA FLATOW: Yeah. Is that protection against long-COVID different if you’ve received two shots versus a booster versus two boosters?

AKIKO IWASAKI: Yeah, that kind of detailed information is not available yet. But I would think that keeping your immune system revved up by the amount of booster doses that are needed will be protective against both acute and long-COVID. So that would be my guess, is that if you’re up to date with your booster doses, it’s probably best in terms of avoiding getting the long-COVID as well.

IRA FLATOW: We don’t know of any harm to getting more boosters, do we?

AKIKO IWASAKI: Yeah. Well, I would never say that there is no harm associated with anything. Because every medical intervention carries some risks. And it is true that there are people who are getting reaction to the vaccines, people who are suffering from long-term consequences after vaccination. And that’s something that we are starting to investigate– these vaccine-associated adverse events.

So I wouldn’t say that there is no risk at all for getting the booster. There is a risk/benefit calculation that one needs to do for any medical intervention.

IRA FLATOW: Let’s talk about something new in the vaccine world. And I’m talking about the development in COVID nasal sprays. There was a study this week from Germany that found a live attenuated nasal vaccine provides special immune protection. Can you tell us about that? Is that promising?

AKIKO IWASAKI: Right. So nasal vaccines, in general, can establish immune responses in the nose, where you first encounter the virus. And that has a lot of advantages. Because if you can prevent the virus from replicating and spreading throughout the body, the less chances of you getting sick or transmitting the virus to someone else or developing long-COVID and other complications. So nasal vaccines are very promising.

The study that you’re referring to from Germany uses attenuated virus to elicit these responses. And there is another vaccine that is also live– an attenuated version of the virus– that’s being developed by a company called Codagenix. And those are already in clinical phase trials. So hopefully, we’ll see the results coming from those studies soon.

IRA FLATOW: You’re also developing a nasal spray for COVID. Can you tell us about what you’re working on?

AKIKO IWASAKI: Sure. So our vaccine is called Prime and Spike. It’s a strategy based on taking advantage of our existing immune response to the spike, and then redirecting that response to the nasal cavity by using a nasal spray that delivers the spike protein itself. And so that works really well in preclinical animal models. We haven’t taken it to human clinical trials yet, but we have a company that has licensed this technology. And that company is trying to raise money to be able to do that.

IRA FLATOW: Yeah. Because I’ve seen thinking that says the nose is right out there out front, literally. It’s the first place you defend yourself from viruses. Why not attack that– bring in the counterattack to that place first?

AKIKO IWASAKI: Exactly. And that’s the whole point of the nasal spray vaccines. Because it does allow you the protection and barrier right at the nose, instead of waiting for the circulating immune responses to detect the virus.

IRA FLATOW: Could we see the day where COVID nasal vaccines may be more common than the shots we have now?

AKIKO IWASAKI: Yeah, that would be a dream come true. Because it does make immunological sense to deliver the vaccine where the protection is needed, which is the nose and the mouth and places that you would acquire the virus first. And a lot of people who might be afraid of needles or hesitant about the current vaccines maybe the nasal vaccine will be a little bit more amenable to taking than the shots.

IRA FLATOW: This is Science Friday, from WNYC Studios. In case you’re just joining us, we’re talking with Dr. Akiko Iwasaki, professor of immunobiology at Yale Med School, in New Haven.

Are you keeping your eye on vaccine developments that are coming in months or years that might be a whole new way of creating vaccines?

AKIKO IWASAKI: Yeah. So we’re in the immunology field developing next generation vaccines and the future generations of vaccines. And a lot of people are putting great ideas to practice, and seeing whether they would be better than the current vaccines. For example, if we can make cancer baculovirus vaccines or things that are cross-reactive against all the variants, that would not require any update for boosters and it would prevent future variants from taking over.

So those types of the new generation of vaccines are being developed in the laboratories. And some of them are even in early phases of clinical trials.

IRA FLATOW: So you go right to the body of the virus instead of those spike proteins.

AKIKO IWASAKI: Right. So that’s the other kind of idea, where, why don’t we include other antigens from the virus, like the nucleocapsid, or some other molecules that are not as frequently mutating? And those will afford us cross-reactive immunity as well.

IRA FLATOW: Wow. Well, thank you, Dr. Iwasaki, for this update. I think we’re all very happy to know what’s going on in the vaccine world.

Dr. Akiko Iwasaki, professor of immunobiology at the Yale Medical School, in New Haven, Connecticut. Thank you for taking time to join with us.

AKIKO IWASAKI: Thank you so much, Ira.

IRA FLATOW: And now for something completely different, a sonic treat from The World According to Sound podcast.


PODCASTER: This is blood surging through a person’s brain.


On either side of your head, right at the temples, the bone thins out enough for sound waves to pass through. So if you’ve got an ultrasound machine and you point it at just the right spot on your head, this is what you hear– blood rushing through the arteries in your brain.


Sonographer Claire Mills, at UCSF, can do a lot with these sounds. She can tell if you’ve got internal bleeding inside your head or whether you might be at risk for a stroke. Right now, we’re hearing three separate arteries. They sound different because of how much blood is flowing through them and how fast.


IRA FLATOW: These sounds are part of a podcast and communal listening series. And you can find out more at TheWorldAccordingtoSound.org.

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