Without protection, measles can be deadly serious

Host Amber Smith: Upstate Medical University in Syracuse, New York, invites you to be The Informed Patient, with the podcast that features experts from Central New York's only academic medical center. I'm your host, Amber Smith.

Measles is a highly contagious virus that can have severe complications, including death, but is easily preventable by a childhood vaccine.

So why are we seeing clusters of measles cases popping up in schools and communities? My guest, Dr. Jana Shaw, has the answers. She's a professor of pediatrics and of public health and preventive medicine at Upstate.

Welcome back to "The Informed Patient," Dr. Shaw.

Jana Shaw, MD: Thank you for having me, Amber,

Host Amber Smith: A measles vaccine was first available in the early '60s. Have we studied what the response was like at that time?

Jana Shaw, MD: Yes, we have some historical and research records that describe the reception of the measles vaccines in the early 1960s. As you and the audience may remember, the first vaccines were available in 1963, and around that time, there was a blend of enthusiasm and skepticism among the public about the vaccine.

Before the vaccine's advent, measles posed a prevalent and serious threat to childhood health, prompting anticipation for a solution among parents and health care providers. However, there existed also a perception of measles as a benign, essentially not serious, infection that offered a lifelong immunity, and that has complicated the public's understanding of vaccination benefits.

In contrast to diseases like smallpox, for example, and polio and diphtheria, which instill fear and were nearly eradicated in the U.S. through vaccination efforts, measles appears to be a more manageable target due to its lack of chronic carriers and non-human reservoirs. So initially the immunization campaign was challenged by this lack of perception that measles is a serious infection in children and that vaccine may not be needed.

In addition, the initial vaccination campaigns in 1967 yielded promising results, and there was a significant reduction in measles cases. However, this sense of progress was sort of short-lived, as cases resurged in subsequent years. It became evident that while vaccination protected certain communities, disparities persisted, with measles disproportionately affecting marginalized populations.

So similarly to today, we still see, for different types of vaccines, that some populations are more or less protected against vaccine-preventable diseases. And some of the concerns are due to access to vaccination or perceived lack of safety or efficacy of vaccination. So those sentiments were not all that different.

Host Amber Smith: What was the death rate for measles like before the vaccine became available?

Jana Shaw, MD: Before the widespread availability of the measles vaccine in the early '60s, the death rate from measles in the United States was notable and varied. The historical data suggests that the mortality rate ranged from approximately 0.2% of reported cases. In other words, that means that for every thousand reported cases of measles, approximately two to three individuals would die from the disease.

However, it's also important to recognize that these statistics may fluctuate based on factors such as access to care and demographic disparities and the presence of concurrent health issues.

In addition, death is only one of the outcomes of measles. But measles can also lead to a number of complications, and in roughly 30% of cases, children or adult can develop diarrhea. It's one of the most common complications, and most of the deaths will primarily occur from infection of the respiratory tract or brain swelling.

And the complications are more common, also, of course, in low-income countries, where the fatality rate can be as high as 4% to 10%.

Host Amber Smith: So were parents back then eager, or were they skeptical, about getting their kids vaccinated?

Jana Shaw, MD: So initially, parents were open to vaccination, with some of the hesitation that I have shared about the need for the vaccine, because in those years, measles was perceived as an infection of childhood that led to lifelong immunity.

And by some parents, it was actually celebrated, compared to smallpox and other serious infections like polio -- those were feared by parents. Measles was less feared, hence the public health officials really had a challenge to help parents understand that measles, although it's perceived as not particularly severe, can have serious complications and can lead to death.

Host Amber Smith: So something must have worked because vaccination pretty much eradicated measles, right? A few years ago, we were talking about it being eradicated.

Jana Shaw, MD: Yes, measles was eliminated, rather than eradicated, in the U.S. in 2000. And in fact, before the initiation of the measles vaccination program in 1963, there were an estimated 3 million to 4 million individuals who contracted measles annually in the United States, and that is essentially the U.S. birth cohort.

Among the reported cases, and, typically, there would be 500,000 cases officially reported, which was a severe underestimation of the burden of the infection, 500 of those would result in death, and 50,000 would lead to hospitalization, and 1,000 individuals, on average, would develop brain swelling due to measles.

So prior to the vaccination program, we had seen a large burden of serious infection and complications from measles, which has led to substantial decline, when in 2000 in the U.S., measles was declared to be eliminated, which essentially means that there is an absence of continuous disease transmission for more than 12 months.

Host Amber Smith: So why are we hearing about outbreaks of measles now?

Jana Shaw, MD: Well, I think the answer will be self-evident as I sort of walk through some of the numbers and the reasons that led to the emergence of measles outbreaks.

For example, in 2009, the United States experienced one of the largest numbers of measles cases since 1992.

There were over 1,200 cases reported, and these outbreaks were sparked by the international importation of the virus by unvaccinated individuals, mostly Americans, and the majority of those cases in the U.S. occurred among individuals who deliberately chose not to receive the vaccine.

So those were cases among individuals who were intentionally unvaccinated. And because measles is so contagious, it facilitates its rapid spread, and it leads to outbreaks in communities that are under-vaccinated.

Host Amber Smith: This is Upstate's "The Informed Patient" podcast. I'm your host, Amber Smith.

I'm talking about measles with pediatric infectious disease specialist Dr. Jana Shaw.

Host Amber Smith: So let's talk about how contagious measles is. Just for example, if one kid who's infected in a class of say, 20 students, how many other kids might become infected?

Jana Shaw, MD: That's an important question, because measles is one of the most contagious viruses we know. It is so contagious that if one person has it, up to 90% of the people close to that person who are not immune will also become infected.

Infected people can spread measles to others from four days before, through four days after, the rash appears. And the risk of transmission is highest when the symptoms may be similar to other respiratory infections, cough, runny nose, fever and sore throat and pink eye. And those are difficult to pinpoint as measles, so at times when people are infected, they may not know they have measles because the symptoms are similar to other respiratory tract infections.

Host Amber Smith: So does this spread through the air when someone coughs or sneezes?

Jana Shaw, MD: Yes, measles spreads through the air. It's called airborne virus, and it spreads through coughing and sneezing.

For example, if other people breathe the contaminated air or touch the infected surfaces and then touch their eyes and noses or mouths, they can become infected. Measles virus can also live up to two hours in an airspace after an infected person leaves an area.

Measles virus is a human species virus, and animals do not spread the measles virus. It's one of the important distinctions from other viruses.

Host Amber Smith: So in that classroom with 20 students, if one is infected, if the rest of them are vaccinated, are they safe from contracting this?

Jana Shaw, MD: Most children who have received two doses of measles, mumps, rubella vaccine would be protected against measles even if the infected individual will enter the classroom. However, it's really important to remember that although measles vaccine works really well, it also is not 100% protective.

In addition, in a classroom, we typically do have some children who either cannot be safely vaccinated or have received maybe measles vaccines but have subsequently developed a condition that sort of weakens their immune system, and, as such, those children will be vulnerable to measles.

So it's really important to remember that the measles immunization program that was rolled out in the '60s in the United States, along with the immunization vaccine requirements, has strengthened the program, but there are still children who are vulnerable to measles, either because they could not be safely vaccinated, or they might have lost protection due to their condition, and therefore it's really important that all who can be safely vaccinated receive the vaccine.

Host Amber Smith: Let me ask you, what happens if there's a measles outbreak in a school and a parent decides to send an unvaccinated child to school anyway?

What is likely to happen in that scenario?

Jana Shaw, MD: The child will contract measles. measles is so contagious, that unless you have a immunity against the virus, you will develop an infection, and hopefully you will not go on developing complications, but you will end up infected.

I should also mention that vaccination alone, for some individuals, if it does not protect them from infection, it will lessen the severity of your disease, so there is additional benefit of vaccination. Not only you are most likely to be protected from infection, but for those with immunity that may not be as strong after vaccination, they are unlikely to develop serious disease.

I should also mention that most schools, and immunization laws for school entry differ by state, most schools will not allow an unvaccinated child to be at school when there is an ongoing measles outbreak. In fact, it's one of the clauses in immunization law for schools, where children will have to be excluded from school if they are not vaccinated and there is an outbreak.

Host Amber Smith: So if an unvaccinated child, or I guess any child, is exposed to measles and contracts measles, are they likely to spread it to other people as well?

Jana Shaw, MD: Absolutely. Yeah, measles is so contagious that the virus can be easily spread to others. And the question is, how many other people can contract virus from that child?

And that will very much depend on the community immunity, or what we used to refer to as herd immunity, right? If a child lives in a community where a lot of children are unvaccinated, essentially there are pockets of unvaccinated individuals that child will spread the infection to all those who are unvaccinated and the child comes into contact with, and in addition to adults who might have lost protection over time or might have chronic conditions that weaken their immune system, such as adults living with cancer or receiving medications for the rheumatological conditions that weaken their immune system.

Host Amber Smith: Well, let's talk about the measles vaccine that's available today, that's on the market today.

How do we know that it's safe?

Jana Shaw, MD: We know the vaccine is very safe because we have ongoing vaccine safety surveillance systems in the United States. The vaccine safety surveillance continues even after vaccine is licensed, so that doesn't mean we stop looking for safety, especially because clinical trials may not be large enough to account for very rare complications.

As such, we know that the measles vaccine is very safe because we continue to look for serious adverse events following vaccination. So as such, we have data that points to the safety of the vaccine. So it's not that we relied on the clinical trial alone. We continue to monitor and look for signals or concerns that could be associated with vaccination. And those signals or events are carefully evaluated by experts in public health, in pediatrics, in infectious diseases, and those who understand how to establish causality.

Host Amber Smith: So I think the measles vaccine is part of MMR: measles, mumps, rubella. But isn't there a version that also protects against the chickenpox?

Jana Shaw, MD: Yes, you are right. There are two different types of vaccines, MMR and MMRV. The MMR stands for measles, mumps, rubella, while MMRV adds protection against varicella, commonly known as chickenpox. Both vaccines are typically administered at ages 12 to 15 months and 4 to 6 years of age.

In certain cases, Amber, the child's health care provider may choose to delay MMRV vaccination to a later appointment or recommend separate MMR and varicella vaccines instead of using MMRV unless there is a specific preference for the MMRV vaccine expressed by the parent or caregiver.

CDC (Centers for Disease Control and Prevention) recommends that we administer MMR vaccine and varicella vaccine separately for the first dose, in the 12 to 15 months of age. And that is because compared to the use of separate MMR and varicella vaccines at the same time, administering the MMRV vaccine resulted in one fewer injection, but it was also associated with a slightly higher risk of fever and febrile seizures. And, therefore, the use of separate MMR and varicella vaccines is recommended for those children 12 to 15 months of age to reduce that risk. However, for the older children, at 4 years of age, the use of MMRV vaccine is generally preferred over the separate injections because it's one less shot, essentially.

Host Amber Smith: So do we know if these childhood vaccines confer immunity lifelong?

Jana Shaw, MD: Yes. The measles vaccines typically provide a long-lasting immunity for the majority of individuals who receive it during childhood. And studies have shown that the measles vaccine induces a strong and durable immune response in most people, and it leads to 99% immunity among those receiving two doses.

There are some exceptions, though. A small percentage of individuals may experience waning immunity over time, especially as they age, and additionally, in rare cases, vaccine failure can occur, meaning that some individuals may not develop sufficient immunity after vaccination.

In addition, while antibody titers may decrease over time, studies also indicate that most individuals with waning titers also have what we call anamnestic response to revaccination, suggesting sustained immunity. So that essentially suggests that even if you receive two doses of MMR vaccine, and maybe you lost titers over time, when you're exposed to the virus or to a booster dose, you would develop heightened immunity, suggesting that those cells that are responsible for immune memory are there lifelong.

Host Amber Smith: You use the phrase " titers." What is that?

Jana Shaw, MD: Titers stands for, essentially, a level of antibodies. Antibodies are molecules that protect us from infection. The antibodies differ by the type of infection. For measles, for example, after infection or vaccination, our immune system responds by releasing antibodies that then serve to neutralize the virus on exposure.

Host Amber Smith: Now, these are vaccines that are meant to be given in childhood, but if there's somebody who wasn't vaccinated as a child, can they still be vaccinated against measles as an adult?

Jana Shaw, MD: Yes, adults can be safely vaccinated against measles as well. And, in fact, adults who have not either had measles or have not been vaccinated should be vaccinated against measles, because, as we know, even in the U.S., even if you don't travel anywhere, it's possible that you may be exposed to someone who has traveled and has brought measles to the country and your community, and you would be at risk for the infection. So it would be best if those individuals talk to their health care providers and seek their guidance on measles vaccination.

Host Amber Smith: You mentioned how contagious measles is. I've read that it has an incubation period of seven to 14 days. So is that when a person is infected, and they can spread it?

Jana Shaw, MD: Yes. The average incubation period for measles is somewhere from 10 to 14 days, which is a period when individuals may not show symptoms yet but can still spread the virus to others.

This also contributes to the prolonged period of infectivity, because people are infected, and they are not aware and, hence, may not take precautions needed to protect those around them.

Host Amber Smith: So compared with other contagious diseases, is this much more contagious because of that? Because people are infectious longer?

Jana Shaw, MD: There are numerous reasons why measles is so contagious. One of them is the incubation period, as you asked. The other is also the airborne spread and the fact that the small droplets, those small infected particles, can remain suspended in the air for several hours, allowing the virus to infect individuals who inhale them.

In addition, infected individuals often have a high concentration of the measles virus in their respiratory secretions, especially during the early stages of illness, and this high viral load then makes them more contagious and makes the transmission more efficient.

The other factor also that's not unique to measles, but contributes to its contagiousness, is that people are contagious even before symptoms appear. So the infected individuals can spread the virus to others during what we call prodromal stages or prodromal phase -- essentially, the phase where you will have fevers and cough and runny nose and maybe red eyes, essentially symptoms that are common for a lot of other respiratory viruses, and you may not know that.

And this early contagiousness makes it challenging to identify and isolate infected individuals before they can transmit the virus. So those are factors why measles is so contagious.

Host Amber Smith: This is Upstate's "The Informed Patient" podcast. I'm your host, Amber Smith.

I'm talking about measles with pediatric infectious disease specialist Dr. Jana Shaw.

Host Amber Smith: So what are the first symptoms of this disease?

Jana Shaw, MD: Some of the first symptoms of the disease include typical respiratory symptoms that you would see with other viruses. So for example, after your infection or first exposure, then infection and following the incubation period, which is the time where people do not show any symptoms, but the virus replicates within the body without causing symptoms, individuals will go on developing runny nose, fever, cold or flu-like symptoms, red and watery eyes. And they also may develop small white spots inside their mouth.

Following that stage, the characteristic measles rash emerges. It starts on the face, and it gradually spreads downward to the trunk, arms and legs over several days. The rash consists of red flat spots that may merge together, forming larger blotchy areas, and also during that time, the individuals may experience high fever and other symptoms. And as the rash peaks, the individuals may experience heightened illness symptoms and severe cough. Some of them may have diarrhea, and that period typically lasts for several days. And after seven to 10 days, the fever goes away, and the rash gradually disappears. So those are the characteristic features of measles.

Host Amber Smith: Are children or adults more likely to develop complications from measles?

Jana Shaw, MD: It depends.

So for children, usually those who are under the age of 5, and especially those who are younger than 2 years of age, they're more susceptible to severe complications from measles. And that's primarily due to their immature immune system.

For adults, pregnant women are particularly susceptible to serious disease. The measles can cause premature labor, low birthweight and also maternal complications, such as pneumonia. For adults, also, those with weakened immune systems, such as those who are on chemotherapy or receive transplants, they are at higher risk for severe measles complication.

In low-income countries, malnutrition can weaken the immune system, and those individuals are prone to serious measles complication.

So the risk groups for measles and for complications sort of differ by age and underlying medical condition.

Host Amber Smith: So people who have compromised immune systems now, they may have had the measles vaccine as children, but with their compromised immune system, are they no longer safe?

Can they no longer rely on the childhood vaccine?

Jana Shaw, MD: Correct. I would encourage all those listeners who may have compromised immune systems that they do talk to their provider about their measles immunity, because they might have lost the protection, either due to the use of chemotherapy or use of steroids or other agents that we use to help, maybe down-regulate, immune systems.

Host Amber Smith: So when we hear about these measles outbreaks in cities far away from Syracuse, is there a concern? Is there a nationwide risk to this localized outbreak?

Jana Shaw, MD: Usually we think of measles, and the risk for measles and transmission, as a local problem because it's important that we remind ourselves that even though the vaccination coverage on a national level for two doses is about, let's say, 93%, to some listeners, that sounds like a great number. It is still below the target of 95%, because we want community protection at at least 95% through vaccination, because measles is so contagious.

But we need to realize that the population immunity can differ greatly between different communities. We have schools where a large number of children might be exempted from vaccination for personal or religious or other reasons. And those schools or school districts would be at greater risk for measles spread and complications from measles infection.

And then there might be school districts where a large number, over 95%, of children are fully vaccinated, and those communities would be at low risk for spread of measles.

So really, I think what we need to look at is at the community-level protection to assess the risk of spread of measles virus.

Host Amber Smith: What should a person do if they're exposed to measles? And would that differ depending on whether they're vaccinated or unvaccinated?

Jana Shaw, MD: The risk differs. If you are fully vaccinated, and you have a healthy immune system, you're probably at low risk for measles to start with. One probably should still contact their health care provider and have that conversation because it may mean that you may have to take certain precautions.

However, if you are not vaccinated, you're at great risk of contracting the infection. And you should certainly contact your health care provider as soon as possible, so not only you can self-isolate, but also have a conversation with your provider in terms of what signs and symptoms to look for and whether there are any interventions that should be done to keep you safe.

Host Amber Smith: How is measles treated these days?

Jana Shaw, MD: Unfortunately, we don't have good treatment for measles. It's one of those infections where we offer what we call supportive care. Essentially, when you end up sick and if you have diarrhea, we'll provide you with hydration. If you develop a pneumonia, which is common, we will support your respiratory system by providing oxygen and making sure you stay well hydrated.

So we don't have any specific antiviral medication to fight this and treat this infection. Vitamin A has been used in low-income countries where malnutrition is common to help to curb the infection, but it's all mostly supportive.

Host Amber Smith: Do you think the youngest doctors today are prepared to care for people who are sick with measles?

Jana Shaw, MD: It's true that many young doctors today may not have encountered patients with measles during their medical training, especially in the regions where vaccination programs have been successful in reducing measles incidence.

However, medical education typically includes comprehensive training in infectious diseases, including the recognition and diagnosis and management of measles and its complications.

Although the clinical experience with measles might be limited, we still provide training and education for medical students and trainees and residents -- those are the doctors in training -- to ensure that they keep measles on their mind, especially in children who are presenting with respiratory symptoms and rash and who may not be vaccinated or have traveled to areas where measles transmission occurs.

And to support my point, the New York State Department of Health has recently issued a health advisory providing details about measles symptoms to increase awareness about the disease because we don't want to miss it when we see it because it spreads so easily.

Host Amber Smith: Is this something where if a child is exposed to measles, do they need to go to the emergency room, or do they call their pediatrician, or how do they handle this?

Jana Shaw, MD: So this would be an example of condition where you probably don't want to go to the emergency room because this is a highly contagious disease. So if you already have symptoms, you probably want to call your health care provider, so your health care provider can guide you in terms of what is the best next step.

If the child or the person is not moderately or severely sick, it's possible they can just be observed at home. However, for those who may have symptoms that require medical attention, they may have to be brought to ED (emergency department). But it would be important that that health care provider notifies ED, so the patient can be quickly isolated, so others in the hospital are not exposed and are safe.

Host Amber Smith: Well, Dr. Shaw, thank you so much for making time to tell us about measles.

Jana Shaw, MD: Oh, thank you for having me, Amber.

Host Amber Smith: My guest has been Dr. Jana Shaw. She's a professor of pediatrics and of public health and preventive medicine at Upstate, specializing in pediatric infectious diseases.

"The Informed Patient" is a podcast covering health, science and medicine, brought to you by Upstate Medical University in Syracuse, New York, and produced by Jim Howe.

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