The Minnesota measles outbreak

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Coming up on Harvard Chan: This Week in Health…

{***Marie McCormick Soundbite***}
An anti-vaccination campaign targeting Somali-Americans succeeded in cutting vaccination rates by more than half. Now a measles epidemic is sweeping through the community. What can this teach us about the anti-vaccination movement and how to keep our children safe?


Hello and welcome to Harvard Chan: This Week in Health. It’s Thursday, June 1, 2017. I’m Noah Leavitt.


And I’m Amie Montemurro.

Noah—this week officials in Minnesota said they expect that state’s measles outbreak—which is already the largest in three decades—will continue to grow.


There have already been 68 confirmed cases in the past month. To put that in perspective—in 2016 there were 70 cases of measles in the entire United States.


This outbreak is notable not just because of its size, but because it was sparked by anti-vaccine groups, who targeted Somali-Americans.


It’s the culmination of a more than decade long campaign that has led to a sharp drop in children receiving the critical measles-mumps-and rubella—or MMR—vaccine.

According to the Twin Cities Pioneer Press, Somali-American children in Minnesota had a vaccination rate of 92 percent in 2004. That rate has dropped to just 42 percent, putting many children at risk for the measles.


And Noah to get some perspective on this you sat down with Marie McCormick, Sumner and Esther Feldberg Professor of Maternal and Child Health, here at the Harvard Chan School.


I spoke with McCormick about the roots of the anti-vaccine movement in the U.S., and the targeted campaign focused on Somali-American parents.

But first I had her explain just what the MMR vaccine is and why it’s so important for public health.

MARIE MCCORMICK: It’s given to children because the diseases that are covered by the vaccine– measles, mumps, rubella– are serious diseases. Particularly measles in younger children can be a lethal disease. One in 1,000 children who get measles will be hospitalized for one reason or another.

It can also, for very young children who would not be able to be immunized– that is, infants under a year of age– they, if they get measles, are more likely to get a very rare but very, very serious side effect called Dawson’s encephalitis, or subacute sclerosing panencephalitis, which is essentially that basically destroys the brain and leaves them demented and dead by teenage years. So it’s, they’re very serious conditions.

Rubella causes major malformations if it’s contracted during pregnancy. And the reason we give it to children is because it’s very hard to nail adolescence down to get it at some time before they’re pregnant. So we know that that works. Mumps can cause sterility in males. So again, it’s something that you would prefer to have on board before you confront the disease.

Measles not only acutely causes problems, but it also suppresses immunity for up to three years. So that means that you are more susceptible to other infections. In the developing world, that means you get your gastroenteritis and your pneumonia and everything else that’s going around. But even children in the United States with suppressed immunity could be subject to more infections if they’ve had wild-type measles.

NOAH LEAVITT: So I think one of the things that’s important when we talk about vaccines is that it’s not just about protecting your child, but there are kind of risks for the larger community. So what are some of the risks if you aren’t vaccinating your children?

MARIE MCCORMICK: What we’re seeing in Minnesota, which is epidemic. Measles is very contagious. It requires somewhere between 85% and 90% of people to be vaccinated so that it doesn’t spread. And what that means is that if you got measles but everyone around you is immune, then it’s nowhere to go. And it will stop with you. When you have– as it is in Minnesota– 40% vaccination rates, then you have the spread of measles very, very rapidly, as was true in the Disneyland epidemic.


And we want to interject here to give some important background information.


You heard McCormick mention the Disneyland outbreak.

In late 2014 and early 2015, 147 cases of measles were confirmed, all tied to theme park.

The disease eventually spread to seven states and two countries.


The exact source of the measles was never identified—but researchers believe that vaccine refusal helped drive the spread of the disease.

As Marie McCormick just mentioned—the ideal vaccination rate to combat measles is between 85 and 90 percent.

But according to scientists at Johns Hopkins—the vaccination rate among those exposed during that outbreak may have been as low as 50 percent.


But where does this vaccine refusal stem from?

McCormick says it generally takes two forms:

Parents who want autonomy over their child’s health—in other words they want to be able to choose whether or not their children receive vaccines.

And those who are concerned over vaccine safety.


And the main catalyst for that is a now discredited, fraudulent 1998 research paper from British gastroenterologist Andrew Wakefield.

That study—which has since been retracted—claimed a link between the MMR vaccine and autism.

McCormick explained for us the significance of that Wakefield paper—and how its effects are still being felt nearly 20 years later in Minnesota.

MARIE MCCORMICK: He raised the question about whether the severe gastrointestinal symptoms were causing leaks in the gut and releasing toxins into the blood, which got into the brain, which caused autism. And he found, in the guts of these children, particles which he called measles particles. And since there was no wild-type measles to speak of, it had to come from the vaccine.

The paper itself does not make that link. But I will tell you, I saw him on 60 Minutes and he certainly was making that link between measles vaccine, gastroenteritis, and autism. What people didn’t realize at that time is that he was trying to develop a measles vaccine– only measles, not measles, mumps, and rubella– under his own patent. That the children came from a group of lawyers who were looking to sue on their behalf for vaccine injury. And that, in fact, the measles particles that he found were not there. And that’s partially sworn testimony from his post-doc, before the vaccine compensation program.

So that, however, generated an enormous amount of alarm– vaccine rates in England fell precipitously– and generated an enormous amount of effort in terms of research. I first got into this area in 2001 with the Institute of Medicine Vaccine Safety Committee, where we looked at the association between MMR and autism, between thimerosal, which is a mercury preservative that was in vaccines, and neurodevelopmental disabilities. And then finally our last report was on vaccines and autism.

And we could find no evidence that supported a linkage of any quality. There was certainly some real garbage science out there that attempted to link it, but these were very, very poorly done studies. The finding was subsequently reaffirmed in another report, probably, I think it’s like 2008. And there’s subsequently been no evidence linking these vaccines to autism. That has not stopped the anti-vaccine advocates.

And in particular, when in 2008, I believe, a group of Somali parents in Minnesota discovered that they seemed to have a disproportionate number of children being treated for autism in the schools, they became alarmed. And Dr. Wakefield swung into action and convinced them that it was the MMR vaccine that was causing this autism. Subsequent studies have shown that there is no increased rate of autism in Somali parents.

But you can also understand their alarm. I mean, these are not families, I’m sure, who had much experience– either with the diagnosis or the treatment of autism- in their home countries. It probably didn’t occur. And so here was this disease, or this neurodevelopmental disability, suddenly appearing among them. And no one can tell them what caused it. And if you want a Nobel Prize, figure out what causes autism.

So they became very alarmed. And their immunization rates plummeted. They had one prior outbreak of measles in 2011. And now, going on this year with up to 50 cases, with I believe eight hospitalized at this point.

NOAH LEAVITT: And so you mentioned the kind of, the anti-vaccine movement. You know, there are kind of like the two main, two main justifications. One is this kind of, don’t bully me into vaccinating my child. And the other is kind of the safety concern. And you’ve talked about that there is this rigorous system to ensure vaccine safety. So what are the precautions and safeguards that are in place to make sure that vaccines are indeed safe?

MARIE MCCORMICK: Well, basically it starts very early on. As you may well know, there are three phases in the approval of drugs, and vaccines are certainly drugs. So there’s the first phase, which is basically testing it for toxicity, the second phase, which is giving it to a fair number of people so you can get some sense of what may be happening, and then the third, phase III trials, are randomized controlled trials. And for vaccines, involve thousands of people. And that’s the stage at which they are approved by the FDA.

Now, they may not be taken up into the immunization schedule until a CIP, Committee on Immunization Practices down at CDC, and other groups look at the data. And not only look at the safety data and the efficacy data, meaning what proportion of cases do they prevent, but also may look at other issues, such as the reason– one of the pieces of evidence that led to the support of the chicken pox vaccine was that it reduced the time out of work for parents. So it was both preventing the chicken pox but also had this economic benefit. So they look at all of the data together and put it into the immunization schedule.

In doing so, they also have to compare the effect of that vaccine versus the other vaccines that are being given at the same time. And the timing of the vaccines is very carefully calibrated, to talk about what infants can handle at a certain point. So for example, you can’t give measles vaccine pretty much during the first year because it may not take. And that’s because they may have some of their mother’s antibodies on board that cross the placenta. So not only is it whether the vaccines are safe, but also what intervals they need to be given in order to achieve roughly 80%, 85% of people being immunized.

Once it’s out in the schedule, there’s what’s called post-marketing surveillance. That really comprises a couple of activities. One is VAERS, which is the Vaccine Adverse Event Reporting System, which anybody who feels that they’ve had an adverse event from a vaccine can go in and fill out the form. It’s done at CDC. They review the forms. Clearly, there are thousands, so they have to set some priorities about which ones they go after. But if it seems like it’s plausible, they will certainly go and investigate that side effect.

They also have the capacity, in what’s called the Vaccine Safety Data Link– the SD sites, which are about seven or eight HMOs– that have very extensive data, both in terms of the vaccines being given and all the medical care that the individuals receive. And they can go through and do specific studies. So for example, they have looked in their population at the association between vaccine receipt and autism and seen nothing in terms of the usual population statistics.

So they, with their millions of people, can go in after some fairly rare diseases, rare conditions. People take this very seriously. And there’s a lot of backstopping in terms of looking at the data and doing other kinds of studies. And then there are, for example, in Atlanta, they have a monitoring system where they look at developmental disabilities. They’ve looked in that population in terms of its association with vaccine receipt. So there are a number of studies. And that’s in the United States.

England has a large system where the general practitioners in the Thames area feed into monitoring. The Danes have their national health system, as they all do, and can look at it, you know, to a fare thee well. So you know, it’s not as if this is an unexamined territory. There are a lot of people looking at it, and consistently, no matter how you do the study. And that’s also important. Any one study may have its limitations. But if you have study after study after study of different types and they all come to the same conclusion, then you’re probably pretty sure it’s the right one.

NOAH LEAVITT: The anti-vaccine movement, it’s not new, I mean, by any stretch.

MARIE MCCORMICK: Oh, no. It actually dates back to the introduction of smallpox and Cotton Mather in Boston, Massachusetts.

NOAH LEAVITT: Right. So this is nothing new. But it seems like in the current administration, it has maybe gained notoriety or more publicity, especially in the last few years. I mean, do you see that it is gaining more notoriety, or is it always kind of been there? People just maybe haven’t noticed what’s been going on.

MARIE MCCORMICK: I think what makes it more visible is the net. There are a lot of opportunities to present material, and through other social media. And so they can have their own blogs. You know, they come up on the searches. And so if you’re doing your research by Google University they’re as equal to come up in the searches as the CDC. In fact, actually, when I first went on the Immunization Safety Panel at the IOM, I asked my students to do a search on immunization safety. And CDC didn’t come up in the first 10.

NOAH LEAVITT: So what came up?

MARIE MCCORMICK: Almost anything else. They now come up in the first 10. So there is a base. I actually don’t know if they are becoming stronger. Pew Foundation has done periodic surveys. And there has been no increase in the proportion of parents who are skeptical of vaccines. A quarter of parents are skeptical, but they can be brought around by their pediatricians, largely. Their pediatricians hold a great deal of clout. So I think it’s only a small proportion who are really the hard core and I’m not sure that that’s growing.

NOAH LEAVITT: And so you mentioned pediatricians hold a lot of sway for parents. So for parents who are on the fence, and either maybe it’s because they want to have autonomy over their children’s bodies and their decisions, or they’re concerned about safety, I mean, what are some of the conversations that doctors should be having with parents? And then what are some questions parents should be asking their doctors?

MARIE MCCORMICK: The American Academy of Pediatrics, among others, has some fairly detailed material about how you should talk about vaccines with parents who have questions. And I think the parents can ask what are the expected side effects. And yes, there are the usual ones, which is fever and soreness. There can be rarer ones. And it is an act of community to take on a risk, even a very, very small risk, to protect the rest of the community. Not only to protect your child, but also to protect the rest of the community.

So there has to be some sense of civic participation, civic responsibility, as well as protecting your own child. The main thing is it’s protecting your own child. With things like the Minnesota situation, different strategies have to be used because you’re talking about population messaging. And there’s a very lovely article by one of the public health people in Minnesota talking about the strategies that they’ve used, that appear to beginning to gain some traction. But it’s taken them almost 10 years.

NOAH LEAVITT: And so I wanted to ask about that kind of– the larger scale messaging. For people in public health, what are some of the strategies that we know do work when it comes to communicating about vaccines, that are effective?

MARIE MCCORMICK: Well, there’s some active research going on in that, and what kind of messaging works. Clearly just laying out the facts doesn’t, because it really only confirms the biases of those who are against your facts. It appears, in some recent work, that one strategy is presenting the pros and cons of both sides, and then presenting your information. And that appears to make people more susceptible to at least listening to your argument. But if you’ve got someone who really feels very strongly, it’s going to be very hard to crack that, very hard.

Other strategies for improving vaccine uptake, for example, occur in terms of public health regulation. And for example, in California, have eliminated all exemptions except medical exceptions to vaccines. I think the other thing to realize is that people talk about a vaccine mandate. It is not mandated that you get your child immunized. What is mandated, if you want a public education, you have to have your child immunized to go to school. There are private schools that have very low immunization rates. And there are, of course, the home schooled group. So it’s not mandated.

The government doesn’t mandate that you have to have your child immunized. They simply say, you want to go to a public school, you have to have it immunized. And it is very clearly articulated. If you are Rand Paul, he said, my kids belong to me and I do what I want with them. Well actually, that’s not true. We have a fairly long history in this country, particularly with child abuse and neglect laws, that say, no, you are not free to do whatever you want to your children. We’ve conquered that one in the 1890s.

And so I think that this notion that the parents had the absolute right to make decisions for their children is challenged almost every day in the sense that if they make the bad decision, then people have the right to step in. And so, you know, I think it’s less the notion of I’m taking the risk for the community than it’s the notion of this kid belongs to me and I can do what I want with this kid. And that’s the notion, I think, that pervades most of the– some of the anti-vaccine groups.

NOAH LEAVITT: And I could see that being a hard sentiment to crack.

MARIE MCCORMICK: Yeah, because we have a very long history in this country, also, of saying that preschool children really are the purview of their parents. Once they get into school and get school age, then we say, yes, they’ve got to go to school and they’ve got to meet certain criteria. But preschool kids tend to be pretty much under their parent’s care unless something really dreadful happens. And so they are free to make some of these decisions that are not necessarily in the best interests of their child.


That was our conversation with Marie McCormick on vaccines and the anti-vaccine movement.


And while she did say that there haven’t been any major changes in vaccination rates among American children—she did say there are still pockets where vaccination rates are extremely low.


McMormick says communities have tried to address this by publishing immunization rates by school to show where children are not being vaccinated.


Coming up next week: An update on Zika virus.

A year and a half after the outbreak first began, we’ll speak with an expert about what we know now about the virus and its health effects, plus should we be concerned about Zika in the U.S. this summer?


In the meantime, you can listen to this podcast any time by subscribing on iTunes or Stitcher, or find us at

June 1, 2017 — Health officials in Minnesota are now grappling with that state’s largest measles outbreak in several decades. As of May 31, the Minnesota Department of Health had confirmed 70 cases of the disease. The outbreak is being blamed in part on anti-vaccine groups who targeted Somali-Americans, leading to a sharp drop in the number of children receiving the measles, mumps, and rubella (MMR) vaccine. In this week’s podcast, we get perspective on the outbreak from childhood vaccine expert Marie McCormick, Sumner and Esther Feldberg Professor of Maternal and Child Health, at Harvard T.H. Chan School of Public Health. We spoke with McCormick about the roots of the anti-vaccine movement, as well as communications strategies to ensure that children receive critical immunizations.

You can subscribe to this podcast by visiting iTunes, listen to it by following us on Soundcloud, and stream it on the Stitcher app.

In the playlist below, Marie McCormick discusses several key issues related to vaccinations: