Scott Webb (Host): This is Children's Health Checkup, where we answer parents' most common questions about raising healthy and happy kids. I'm Scott Webb, and today we're covering what parents need to know about measles. And I'm joined today by Dr. Michael Sebert. He's the Medical Director of Infection Prevention and Control at Children's Health and Associate Professor at UT Southwestern.

 Doctor, it's so nice to have you here today. We're going to talk about a hot topic, something that's really in the news and social media and just all over the place, which is measles. So let's start there. What are measles and how do they spread?

Michael Sebert, MD: Measles is a highly contagious viral infection that spreads through the air. It's one of the most contagious infectious diseases known, and although close contact with someone who has measles poses the most risk, the measles virus can remain in the air and it can actually infect someone else even up to two hours after the person with measles has left the area. So, the risk for spread of measles can be quite high. 

Host: It feels like we had tackled measles. It feels like we had eliminated measles, but now I'm hearing about it all the time. As I said, news, social media, hearing about outbreaks and deaths related to measles. Maybe you can just give us a sense, like how did measles make a comeback? Like what's causing the rise in this measles outbreak?

Michael Sebert, MD: Your impression is correct. Measles was actually declared to have been eliminated from the United States back in the year 2000. And then, even more broadly from North and South America in 2016 by the World Health Organization. And achieving that sort of measles elimination status requires the absence of any local transmission of the infection for at least a year.

Now that's despite the fact that there may still be some imported cases that are associated with travel that still continue to occur. Our elimination status, however, would be reversed if there were a sustained chain of measles transmission in the country that lasts for a full year. That almost happened back in 2019 with a prolonged outbreak that was focused in the New York City area, but fortunately ended before a full calendar year.

So we do still have in the US, that measles elimination status, but because measles is so contagious, it requires a particularly high level of vaccine coverage in the population to prevent outbreaks. So, the CDC estimated that in 2013 it was just under 93% of children who were entering kindergarten who had received the required two doses of the MMR vaccine.

That's below the 95% threshold that's generally considered to be acceptable, generally accepted, as being necessary for preventing outbreaks. And the further a community is below that 95% threshold, the easier it is for measles to continue to spread once the first case occurs. 

Host: So we had basically eradicated measles at some point, right? Where you said around 2000. And it is making a comeback, of course. And whether that's because specifically that there are areas or pockets that are below the 95%, that's beyond my level of expertise. But because it's so transmittable as you're saying, right? Because it's so contagious, it would probably help us to know like what are the typical symptoms of measles and the potential complications, like what should we be on the lookout for?

Michael Sebert, MD: Sure. So the first thing that comes to mind for most people when they think about measles is the rash. There is, however, a first stage of the illness, for several days before that, when the patient typically has a high fever and other symptoms including cough, red eyes, and a runny nose. The illness is contagious during this early period when it may be rather difficult to differentiate it from other viral infections.

When the rash starts though, after these initial symptoms, the typical measles rash consists of red spots that begin up on the face around the hairline and then spread down, across the entire body. Complications of measles are unfortunately common, so about one in five unvaccinated people in the US who develop measles, require hospitalization. About one in 20 children with measles developed pneumonia, which is the most common cause of death from measles in young children. Inflammation of the brain, swelling called encephalitis, happens in about one in a thousand children with measles and can result in seizures, deafness, or other permanent disabilities. So the WHO, World Health Organization estimates that in 2013, measles still caused more than a hundred thousand deaths worldwide.  

Host: So Doctor, now that we know the risks and complications of measles, can you tell us a little bit more about the vaccine? What's in it and how effective is it? 

Michael Sebert, MD: So the MMR vaccine is about 93% effective with a single dose. This is a live attenuated vaccine which children get their first dose when they are 12 to 15 months of age. The second dose is then given between four and six years of age.

Host: So you say the one dose is pretty effective, fairly effective, but the second dose is really what we hope that all folks get. And I'm just wondering if a child or an adult misses the window to be vaccinated, is it too late at a certain point?

Michael Sebert, MD: No people can start or complete their measles vaccine series at any age beyond infancy. There are some children or adults, however, who are severely immunosuppressed because of certain medical conditions or because of medications that they're taking that weaken the immune system. And these individuals cannot receive the MMR vaccine, but their family members can receive the vaccine. And their getting it, helps to protect the person with the weak immune system indirectly.

Host: Okay. If one person can't get it, but everyone around them in their circle and their family and friends is all vaccinated, that's a good thing. And you know, we're hearing about these outbreaks as we talked about. Is there ever a time where a child is just too young for the vaccine? In other words, you know, if one of these areas, these pockets where there is an outbreak, is it possible that they can get that first dose at least maybe early?

Michael Sebert, MD: So during an outbreak, children as young as six months of age can be vaccinated with MMR in some circumstances. So in our current outbreak in Texas, public health authorities have recommended this step of early vaccination in some of the most heavily affected counties. Early vaccination is not currently recommended in the Dallas-Fort Worth area, however.

And, parents should be aware that if a child gets the MMR vaccine before 12 months of age, that vaccine dose doesn't count toward their regular immunization requirements. So repeated vaccination is then necessary in the 12 to 15 month age period.

Host: I see what you mean. Might be able to get the vaccine or have a child get it early because of the outbreak, but they still need to be on their regular schedule. Okay. So if a parent suspects that their child has measles, what do they do? Do they go see their medical provider or the pediatrician? Do they go to the hospital?  

Michael Sebert, MD: They should call their pediatrician first to discuss the child's symptoms and for advice about what to do next. They should let the physician's office know in advance before bringing the child in if they suspect measles, so that the office can take appropriate precautions. And it's important also to keep the child out of school and public settings, where the measles virus could be transmitted while they're waiting for medical advice and evaluation.

Host: You know, Doctor, I've seen I'm sure we all have, just misinformation, you know, I just feel like things that I'm reading out there, vitamin A, cod liver oil that can prevent or cure measles. Maybe you can help us to sort of understand the science anyway of these so-called remedies. Are there any truths behind this, or is it all mostly myths if you will?

Michael Sebert, MD: Those are very timely questions. So with regard to vitamin A, there is no evidence that Vitamin A can prevent measles. What is known is that in children, in the developing world, the seat of vitamin A, can decrease the rate of mortality from measles. So, for patients, with measles, particularly those who are hospitalized, even in this country, vitamin A is one step that is recommended. However, vitamin A is not prevention and it's not a cure. And so, we really need to remind everyone listening that the MMR vaccine is very safe and it's the best way of keeping your child healthy and preventing outbreaks like the current one in our state.

Host: Gotcha. Yeah. So MMR for sure. The vaccine that's most important. That's the main headline here today in terms of preventing measles. And then some of this other stuff like vitamin A maybe is used, maybe can be used, but is not prevention, does not cure. I'm with you, Doctor. I really appreciate your time today, your expertise.

Just give you a chance here at the end. Anything else? Like what do you really want folks to know about measles, the MMR vaccine, you know, just make your point here at the end.  

Michael Sebert, MD: The first most important message is of course that the MMR vaccine is so very safe and effective. And that's what will be necessary really for ending an outbreak like the one that we're dealing with here in Texas. The other thing to point out that I think is quite interesting and that has not gotten nearly as much attention is some recent research indicating that the risks from getting measles don't necessarily end when the child gets better. It appears that getting measles can also make your child more vulnerable to a wide range of other infections by erasing parts of the immune system's memory, even the memory of previous infections from which they've recovered. The sort of immune memory is something that we all depend on to keep us healthy. And if measles causes gaps in that memory, it means that we're more vulnerable to other infections.

Host: Hmm. Yeah, it's interesting and it's a lot to take in, and I know that this outbreak right now in Texas as folks are hearing this, is like that's the number one concern. But long term, of course, the points you're making here MMR vaccine, get vaccinated. It's safe, it's effective. So appreciate your time, your expertise, everything. Thank you so much.

Michael Sebert, MD: Thank you.

Host: And visit children's.com/measles for up-to-date information. I'm Scott Webb. And thank you for listening to Children's Health Checkup. If you found this podcast helpful, please rate and review or share this episode, and please follow Children's Health on your social channels.