Science Friday - The science and politics of the new mRNA flu vaccine

Episode Date: October 10, 2026

A new mRNA flu vaccine made by Moderna was approved by the FDA in August, and is currently available for people aged 50 and over. The promise of an mRNA vaccine for flu is that it can be spun up more quickly than a traditional vaccine, meaning it could better match the flu strain that’s circulating.  Is that what happened this year? How are the side effects? And how has dysfunction at the health agencies impacted rollout? Flora discusses these questions and more with vaccine researcher Anna Durbin.Guest:Dr. Anna Durbin is a vaccine researcher, professor of international health, and director of the Center for Immunization Research at the Johns Hopkins Bloomberg School of Public Health.Transcripts for each episode are available within 1-3 days at sciencefriday.com. Subscribe to this podcast. Follow our show on Instagram, TikTok, Facebook, and Bluesky @scifri and sign up for our newsletters. Got a science question that’s keeping you up at night? Call us: 877-472-4374 Hosted by Simplecast, an AdsWizz company. See pcm.adswizz.com for information about our collection and use of personal data for advertising.

Hey, it's Flora and you're listening to Science Friday. A new MRNA flu vaccine made by Moderna was approved by the FDA in August. It's currently available for people age 50 and over. That was the age group studied in the clinical trial. Now, the promise of an mRNA flu vaccine is that it could be spun up quicker than a traditional vaccine, meaning in theory you could get a better match to the year's flu strain that's circulating. Is that what happened this year? How are the side effects going? And how has dysfunction at the health agencies impacted the rollout? Those are some of the questions we're going to tackle today with Dr. Anna Durbin, vaccine researcher and director of the Center for Immunization Research at the Johns Hopkins Bloomberg School of Public Health. Anna, welcome to Science Friday. Great. Thank you so much for having me, Flora. Thank you for being here. Is this year's MRNA vaccine a better match with the circulating strain of fluid?

This MRNA vaccine contains the exact same strains as the inactivated and other vaccines that are being used this season. And the reason for that is our current method of choosing which flu strains go into the vaccine is based on a meeting that we have twice a year. Once is to pick the northern hemisphere strains. That meeting occurred in March. The second meeting just occurred last week, and that's to pick the strains for the southern hemisphere. But it's October. So the strains that we picked in March, we're hoping will be a good match for what's circulating in the fall. But the biggest issue we have right now is because of the amount of time it takes to make our traditional flu vaccines, we need a long lead time in strain selection.

And that's why we think that there's great promise with the MNRNA vaccine that we can make those vaccines so much more quickly. But it's just not the ability to make the vaccine. We have to have FDA regulatory guidance on which strains to include in that vaccine. As I said, that meeting occurred in March of 26. Is that an FDA meeting or a WHO meeting? There's two. There's a WHO meeting, which picks the strains globally. And then there is an FDA meeting, which specifically picks the strains for the vaccines that are being used in the U.S. So why didn't we have an FDA meeting after March? That is a great question. I will say at the meeting in March, several members of the committee suggested that very thing. What the members of the

committee said is this is an MRNA technology. We can make the vaccines faster. Why don't we have meetings more frequently? And the FDA has heard this on a couple of occasions. And I think, you know, the agency is looking at that. They're evaluating that. And they're trying to determine whether or not that will happen. I'm very curious and interested to see if we will have a meeting over the summer for the Northern Hemisphere as opposed to just in March. So I think, you know, the jury's out on that. We don't have a firm answer yet, but we're encouraged that the agency is considering it. It doesn't seem that hard to hold a meeting. It doesn't, but there is bureaucracy and with the current administration in the FDA and, you know, just in HHS, whether or not that's

going to happen, I think, as yet to be seen. So this is the first year that this MRNA flu vaccine is available. Is it being evaluated in some way? And how? So every year, CDC as well as other groups, influenza surveillance systems occur throughout, not just in the United States, but globally. So there's different groups out there that evaluate, one, what is the flu activity, what strains are happening, how is the vaccine coverage and how is the vaccine effectiveness during that season? So that will occur this season just as it occurs every season.

You know, I think one of the great problems that we have right now is the reduction in workforce that we saw at CDC and FDA and at IH, frankly. about a year ago. And that, you know, having to do more with fewer people is difficult. But we will look at overall what was the match between the strains and influenza. I think what I'm really interested to see in this coming influenza season is whether we will get some indication of effectiveness of the mRNA vaccine compared with the historical standard vaccines that we have. Does it offer better protection? Exactly. Exactly. I haven't seen uptake numbers of the MRNA vaccines.

You know, there's some obstacles, I would say, to getting the MRNA vaccine this year because we don't have an ACIP recommendation for that vaccine for reasons that the ACIP no longer exists. That's the CDC's advisory committee on immunization practices. It's been embroiled in a legal battle after RFK dismissed part of the panel. Exactly. It's that committee that makes recommendations about how. vaccines can be used. The FDA makes a recommendation about should a vaccine be used. Is it safe? Does it have adequate effectiveness? Once that decision is made, then it goes to ACIP to recommend

how it should be used. And we don't have a recommendation. And unfortunately, a lot of insurance coverage of vaccines is linked to that recommendation by ACIP. So does this flu-MRNA vaccine seem to have stronger were side effects like the MRNA COVID vaccine compared to the non-MRNA COVID vaccine? Most likely it will. And even in the clinical trial, we did see those same types of side effects that we saw with the COVID vaccine. So you'll have redness, fatigue, a little bit of muscle aches and pain, maybe a low-grade fever. And why is that? We think that that occurs because of that what we call lipid nanoparticle that the mRNA is contained. And it. It's really, you can think of it as a fatty balloon that contains the MRNA.

That fatty balloon is recognized by your body as something that it needs to react to in order to get a good immune response. So your body, your immune response is reacting to that fatty envelope that contains the mRNA and signaling to your immune system that it needs to send out what we call cytokines, which are like chemical mediators that stimulate your immune system. those chemical mediators cause redness, swelling. They draw in your cells that fight infection. They draw those to the site of where the vaccine was given.

So you get redness, swelling. And then they also travel throughout your body, the chemicals that can cause, as I said, muscle aches and pains, low-grade fever, that sort of thing. It's really an indicator that your immune system is seeing that vaccine, and it's mounting a strong immune response. And the traditional or the vaccines that are not MRNA, they don't have a fatty balloon? No, they have something that doesn't work so well to stimulate the immune system, and that's Alam. We've used Alam for generations. It's what we call an adjuvant or a helper to help the vaccine

stimulate the immune system, and it just doesn't work quite as well as that fatty balloon. So is anyone trying to engineer out the side effects, or is this just evident? that the vaccine is working? So this is a lot of evidence that the vaccine is working, and we don't try to necessarily engineer them out. We try to manage them. So what I recommend people do is a couple hours after they get a vaccine, they can take a Motrin or a Tylenol that can tamp down some of those side effects. So do you have a sense of how difficult or easy it is to find this MRNA flu vaccine in pharmacies? It is in pharmacies. It's in, you know, your local pharmacy has it. You can

call ahead and make sure. The other thing that I advise patients and people who ask me about is find out before you go whether or not your insurance is going to cover that. The vaccine without insurance costs more than $100. So you, you know, you have to take that into consideration. So ACIP didn't recommend it, which means insurance doesn't have to cover it, but some insurance may still cover it. Right. Some insurance is seeing. the value in this and understand that it's a good use of their money and that they will cover the vaccine. You know, MRNA vaccines have become so political in this country. What's happening in other countries with this technology? Well, in Europe, for instance, the MRNA vaccine,

influenza vaccine that was approved here by FDA over the summer, actually in Europe, it was a combination of RNA influenza COVID vaccine that was approved. that was not submitted for approval in this country. This is my opinion only. I haven't talked with anyone at the company, but I think that it was a decision that they felt it would be a huge mountain to climb to try to get a combination new MRNA COVID influenza vaccine approved. The rest of the world has embraced MNR technology. I will say my concern is that if we don't invest more in MRANA vaccine technology, the U.S. will fall behind in terms of that technology and in terms of vaccine development. Do you see that happening? Do you feel like there are signs of that already?

Well, we know that the U.S. government, the NIH, recalled, I think, $500 million of investment in M RNA technology. So it has already happened. And there are other countries, Europe, China, that are moving forward. They understand the benefits, that MRNA vaccines are probably vaccines of the future. And if we don't invest in this technology, we will fall behind. What's the effect for public health? Well, the effect for public health, for instance, if we look at what happened with COVID and how quickly we were able to have effective vaccines against COVID because of this technology,

the fear is there's another pandemic. there's a new pathogen. And if we don't have the technology and we don't make the vaccines here, we may not have access to them. And we saw that in COVID with other countries. You know, we saw vaccine nationalism. And MRNA vaccines did not make it to many, many countries because they did not manufacture them or have the approvals, whereas we had it here in the United States. So the concern is, if we don't have that vaccine technology moving forward in the country, we may lose out in another emergency, another pandemic. Even in terms of just MRNA technology for vaccines, other routine vaccines, we may not have access to them until many years later. If we don't

invest in those vaccines here, make those vaccines and have them approved here. Dr. Anna Durbin is a vaccine researcher and director of the Center for Immunization Research at the Johns Hopkins Bloomberg School of Public Health. Thank you for being here today. Oh, it was my pleasure. Thank you so much. This episode was produced by Shoshana Buxbaum. Thank you for listening. I'm Flora Lichtman.