Vaccinated or not, we’re on the brink of a measles epidemic

Measles is making a comeback. Ongoing outbreaks in Pennsylvania, South Carolina, Texas, and Utah have documented hundreds of cases, mostly among unvaccinated people. And while local and federal politicians debate the definitions and impact of those measles-associated deaths, health experts worry that we’re overlooking the real problem: the threat of a full-scale epidemic. Today, we talk to one of those experts – epidemiologist Michael Mina https://crcs.seas.harvard.edu/event/michael-j-mina-md-phd-harvard-th-chan-school-public-health-harvard-medical-school – to figure out who’s most at risk and whether there’s any way for us to turn this epidemic around. Interested in more health and medical news? Email us your question at [email protected] mailto:[email protected]. Support public media with NPR+ and enjoy perks for over 25 podcasts like this one. This show’s perks include sponsor-free listening. Learn more at plus.npr.org http://plus.npr.org. See pcm.adswizz.com https://pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences. NPR Privacy Policy https://www.npr.org/about-npr/179878450/privacy-policy

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• 0:22Regina Barber?

  Remember the schoolyard rhyme, "Miss Lucy had a baby"? Some people jump rope to it, some people learned a hand clapping game, and there was always this one line, "Measles," said the doctor, "mumps," said the nurse, "nothing," said the lady with the alligator purse. The funny thing is that when I was a kid, measles and mumps weren't super common. Researchers developed a combined childhood vaccine for measles, mumps, and rubella in the 70s. It was so effective that measles was declared eliminated in the States in 2000. So, most people in the US, including me, haven't ever experienced it. But measles is making a comeback.

• 1:06Regina Barber?

  Right now, there are ongoing outbreaks, hundreds of cases, mostly among unvaccinated people, documented in states like South Carolina, Texas, and Utah. In Pennsylvania, where the outbreak is biggest, the state health department has reported 792 cases with four measles-associated deaths. And that last term measles-associated deaths has prompted a lot of conflict between politicians like Health Secretary Robert F. Kennedy Jr. and Pennsylvania Governor Josh Shapiro.

• 1:36Speaker 02

  We're trying to figure out whether, you know, who those deaths were and when they actually happened, and we can't figure it out.

• 1:43Speaker 03

  I blame RFK and people like him, who have spread misinformation and disinformation.

• 1:49Regina Barber?

  But while all these politicians argue, health experts worry that we're overlooking the real problem.

• 1:55Speaker 04

  I would say we are very much on the road towards an epidemic.

• 2:01Regina Barber?

  This is Michael Mina. He's been studying measles for the last 15 years. He's an immunologist and epidemiologist, plus the chief medical officer at biotech companies Invivid and Truvia.

• 2:13Speaker 04

  We could certainly start to see a greater explosion of measles cases as we move into the future. I think it's very likely that the United States will probably lose its elimination status, you know, towards the end of this year.

• 2:25Regina Barber?

  So today on the show, the measles outbreak, which deaths are caused by measles versus which ones are associated with it? And is there any way for us to turn this epidemic around? I'm Regina Barber, and you're listening to Short Wave, the science podcast from NPR.

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• 4:00Regina Barber?

  Okay, Michael, so before we get into this current measles outbreak, can you explain what the measles virus does to our bodies?

• 4:07Speaker 04

  Yeah, measles is much more than just a fever and a rash. Measles causes a tremendous amount of damage to your immune system. All sorts of organs that are involved in your immune response are really under attack.

• 4:21Regina Barber?

  Yeah. In fact, you are one of the researchers who discovered something called immune amnesia caused by measles. What is that?

• 4:28Speaker 04

  Yeah, immunological amnesia associated with measles is what I think of as one of the most substantial or consequential effects of getting a measles infection. An individual gets infected with the measles virus. The immune cells in the lungs pull that measles virus in through the tissue, through the lungs, and bring it into what we call the lymphoid tissue. This is the system in our body where the immune cells live, and then where they grow, and where they're maintained and develop immune memory and protection. Well, the measles virus has this nasty trick. It gets presented to our memory cells, and instead of getting gobbled up by them or, you know, destroyed by them, it actually starts attacking them.

• 5:11Speaker 04

  And it starts eating away at our immune memory cells, just like somebody with amnesia maybe has to go through a process of relearning, whatever it might be, that they have forgotten. Immunological amnesia is where a kid or an individual might have spent the last 10 years of their life going through the sicknesses of childhood to build up a protective immune system so that they can live pretty comfortably for the rest of their life. But now you've just erased a lot of that. And what we saw was that a simple measles infection that might look simple on the surface can actually be deleting up to 70% of somebody's entire immunological memory pool, making them at very high risk for other infectious diseases for years.

• 5:56Regina Barber?

  And this isn't just deleting, like, how to fight measles. It's like other things, too, other kind of learned behavior against other viruses. Is that, is that correct?

• 6:07Speaker 04

  That's right. And in fact, we call it the measles paradox now.

• 6:09Regina Barber?

  Yeah.

• 6:10Speaker 04

  So at the end of a measles infection, you end up with extraordinarily powerful anti-measles protection.

• 6:17Regina Barber?

  Right.

• 6:18Speaker 04

  But at the expense of having lost potentially tremendous amounts of protection against RSV, or rhinovirus, or coronavirus, or E. coli, and all sorts of things.

• 6:27Regina Barber?

  Yeah, so this claim that, like, oh, if you get it, you'll be stronger, you're saying in this specific case, you'll be stronger against measles, but maybe you're going to be weaker against all this other stuff you got before.

• 6:39Speaker 04

  That's, that's exactly right.

• 6:40Regina Barber?

  That's devastating.

• 6:41Speaker 04

  It is devastating. We actually, what we saw was in the pre-vaccine era, when most children were getting measles, we found that this process of measles immune amnesia was linked to about half of all childhood infectious disease deaths against everything else.

• 6:58Regina Barber?

  Oh, my gosh.

• 6:59Speaker 04

  And so when you saw a massive, massive impact. And so when we got rid of measles from the community, we saw these amazing reductions in all-cause mortality from other infectious diseases.

• 7:10Regina Barber?

  Wow, because then they kept their immunity from those things.

• 7:13Speaker 04

  That's right. It wasn't the vaccine itself. It was the not getting measles that had this downstream benefit of saying, you get to keep your immune memory and your protection. So the vaccine is almost like an immune-preserving tool as well.

• 7:26Regina Barber?

  Yeah, so there's a lot of different jargon that's been thrown around about this recent outbreak. Last month, for instance, an infant in Lancaster County was declared by the Pennsylvania Department of Health to be a measles-associated death. But the local coroner disagreed and said that the baby died from a ruptured spleen. So let's talk about this specific term. Like, what's a measles-associated death?

• 7:49Speaker 04

  Yeah, it's, it's a great question, and I hope we come back to that particular case a little bit, because it's a really rare situation. But a measles-associated death is usually, it's sort of, I would say, a looser term than saying measles caused this death. It is that measles had an association with the death. The way that I like to think about it is, if you take a step back and say, would this death have occurred had the individual not gotten measles? So this is where a lot of the disagreement comes from, like, how do we use this term?

• 8:23Regina Barber?

  Right. Yeah, and you wanted to mention, why is this case so interesting?

• 8:26Speaker 04

  Well, the splenic rupture case, I think, is a really interesting case because it just might be what I would consider the, the one-in-a-million or the one-in-10,000 time when somebody maybe truly did die with measles, but not because of measles.

• 8:45Regina Barber?

  Hmm.

• 8:46Speaker 04

  A lot of people would say, well, that, that sounds nuts. Splenic rupture, the child had measles, of course it was because of measles. But we can look at the literature, and we could look at the whole history of measles in the pre-vaccine era, and all of the data we've had of measles cases, including many pregnancies with measles in the past, when measles was common. And across all of the body of literature, there isn't a single

• 9:11Speaker 04

  Reported case of a splenic rupture in a newborn as a result of these infections. And so I think we want to avoid trying to make inferences when we don't actually have the data. And I worry that in this case, there was so much momentum to want to drive a causal link that, you know, it's really getting outside the bounds of what is responsible from a public health perspective.

• 9:37Regina Barber?

  Yeah, so you're saying that when, when the death is designated measles association, we don't always know how strong that association is.

• 9:46Speaker 04

  That's, that's right. And we should qualify it. And if we, if we have uncertainty, we should feel very comfortable saying when we're uncertain. It's sort of like psychology 101. You know, if you're trying to gain trust of somebody, like honesty is the best policy. And I think part of being honest in public health is being really clear about what your uncertainties are, along with your certainties.

• 10:07Regina Barber?

  Yeah. So speaking of uncertainties, I just want to briefly talk about the science here because RFK Jr. has suggested that getting the measles could be beneficial. He said at an Amish State Fair in Pennsylvania that it could be cured by vitamin A and chicken soup. So let's just set the record straight here. Is there a cure for measles?

• 10:27Speaker 04

  So there is no cure for measles, at least not right now. The cure is to get through the infection and build immunity. Vitamin A is a treatment for measles, specifically in vitamin A deficient kids. So for those individuals, giving them vitamin A supplementation before, you know, or during a measles infection can be life-saving. So that part, there's a lot of truth there. But I would not call vitamin A a cure for measles. There currently is no antiviral for measles that really beats down the virus enough to cure us of it.

• 11:03Regina Barber?

  Yeah. Let's zoom back out a little bit. There's clear danger for people who are unvaccinated and in these immune compromised groups. How worried should people be if they are vaccinated with this measles outbreak?

• 11:16Speaker 04

  The measles vaccines work extremely well. We can look, unfortunately, on our own soil today. We can actually say, okay, what do we know from just outbreaks over the last few years? And from those outbreaks, we know that there have been tens of thousands of exposures amongst vaccinated individuals and just a handful of vaccine breakthrough cases. So probably if we had a crystal ball and we could say, what is the true efficacy of the vaccine right now across the population? We'd probably say that today, it's something like 99.8% effective to prevent measles. So the good thing for listeners right now, I would say, is that the vaccine protection,

• 12:01Speaker 04

  if you're healthy, if you're not immune compromised, if you were twice vaccinated, you know, you really don't have a lot to worry about. But there are lots of people who do have a lot to worry about. Older individuals, people who are immune compromised, for which there are millions in this country.

• 12:17Regina Barber?

  And for kids, that babies that haven't gotten the shot just yet.

• 12:20Speaker 04

  That's right. There's every year that, you know, there's millions of children at any given time, every year, who are not old enough to get the shot.

• 12:27Regina Barber?

  Yeah.

• 12:28Speaker 04

  So it means millions of kids are at risk at any point in time in the country.

• 12:31Regina Barber?

  Yeah, let's talk about that. You said earlier that the US might lose its elimination status and that we may be in this epidemic, this measles epidemic, right now already. So what would that look like?

• 12:43Speaker 04

  What we've seen to date is really isolated outbreaks. But as those isolated outbreaks get larger and larger, as we're seeing in Pennsylvania, and at the same time as we see the under vaccinated or the susceptible population get larger and larger, those two things start to conjoin. And you might start to see one outbreak over here in Kansas hit up and bump up against a new outbreak over here in Colorado. And all of a sudden, you have two outbreaks that are actually becoming one. We saw that in Texas last year, where we saw these outbreaks no longer look so isolated. And that's what happens with something like measles.

• 13:25Speaker 04

  It's so infectious and so transmissible that as the outbreaks get large, it's a simple probability. And that's when we start to see a small outbreak turn into what we might think of as an epidemic.

• 13:38Regina Barber?

  Do you think that there's a real chance we possibly could reverse course? Like, is there hope?

• 13:43Speaker 04

  I think there's kind of two answers to that. On the one hand, we have such a high number of immunized people or of no longer susceptible people in this country. It's not like 30% of the population is susceptible. So on the one hand, we'll see outbreaks, and if they get big enough, they have the opportunity to burn themselves out. That's natural herd immunity. Do we want that? We don't want that.

• 14:10Regina Barber?

  No, because people will be hurt.

• 14:11Speaker 04

  That's right. That's not the way to, to hope that our epidemics go away. Do I think that there's a way, though, to prevent that? I don't think that there is at this moment in time. I mean, just to be real, I think everything that's happened in the social discourse, the approaches we took with coronavirus vaccines, the reality is there are very large fractions of the country.

• 14:33Regina Barber?

  Yeah.

• 14:34Speaker 04

  Potentially massive proportions, you know, who feel very strongly, and it has sort of led to extreme opinions about whether to get vaccinated, whether to get children vaccinated. Once you lose trust in something like vaccines or public health more generally, I think it's very, very hard to gain back. Should we just keep beating the same drum and just hoping that somehow it reverses? No. And should we ridicule and criticize people who don't get vaccines because they truly don't know and they love their kids? No. We have to think of new approaches to reach consensus, to rebuild trust. It's going to be on us to make sure that we reimagine how we do public health and how

• 15:17Speaker 04

  we reach people who don't necessarily trust us.

• 15:21Regina Barber?

  It's hard to do, but it's necessary to do, right? Thank you so much, Michael, for coming to speak with us about measles.

• 15:29Speaker 04

  Thanks so much for having me.

• 15:32Regina Barber?

  This episode was produced by Hannah Chin and edited by Lauren Gonzalez. Tyler Jones checked the facts, and the clips you heard at the top of the episode were from CNN and NBC 10. Jimmy Keighley was the engineer. I'm Regina Barber. Thank you for listening to Short Wave from NPR.

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