Vaccination can safely prevent a sometimes deadly disease
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 was declared eliminated from the United States in the year 2000, thanks to better measles control, including a highly effective vaccination program. But today, measles outbreaks among children are being reported, and the presence of the disease is becoming more of a concern.
Here to talk about this is pediatric infectious disease specialist Dr. Jana Shaw. 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: Do we in Central New York have reason to be concerned about measles right now?
Jana Shaw, MD: That's a great question. It's a timely question. As you mentioned, we have recently heard of outbreak in Ohio, which is not all that far, and there have been other outbreaks in the country in recent years. The risk of measles in our communities really depends on the level of vaccination coverage.
We have a very effective and very safe measles vaccine that's routinely given to children at young ages, and once children are fully vaccinated, the risk of measles is very, very, very small. So, in our communities, as long as we are surrounded by people who are fully vaccinated, the risk should be very low.
The only way to establish how many children were truly vaccinated is really to look at records of vaccination. And those are typically available through schools. As you know, measles vaccine is required for school entry, and schools keep careful records of all those children. So before we started with this talk, I took a quick look at some of the schools in the surrounding area because that's the easiest way to really inquire how at risk we might be when it comes to measles, and most of the major schools in our communities have children fully vaccinated, so that's great news.
Host Amber Smith: So that's great news. But if this disease was supposedly eliminated in 2000, why is it coming back?
Jana Shaw, MD: It is coming back because we, as Americans, we like to travel. We travel abroad. We go to places where measles continues to be transmitted, and those who are not vaccinated get infected and bring it back to our communities.
And unfortunately, we have seen a rise of vaccine hesitancy and vaccine refusal that not only affected COVID vaccines, but also affected measles vaccines or other childhood vaccines. So we do see pockets of children who are not vaccinated. Those children are typically geographically clustered, meaning we see schools and communities where we see large numbers of children without measles vaccination. And those are communities where we will see outbreak. Those travelers who came from abroad will bring the infection unknowingly and will transmit it to communities without pre-existing vaccine immunity.
Well, so what is important for us to know about measles? Measles is a very contagious virus. Humans are the only hosts. It is a virus that, typically, when we talk about the level of contagiousness, one infected person can easily infect up to 18 people around them who are not vaccinated. So one of the highest rates that we've seen is for measles.
It is a respiratory virus. So, nowadays everybody probably knows what that means, as we've gone through COVID. Similarly to COVID, this virus is transmitted through respiratory droplets, but it can also be transmitted via airborne mode of transmission, which means it carries through the air. It can stay in the air for a couple of hours, even if the infected person left the area. So it makes it a very challenging virus to contain because it infects a lot of people who are not immune and also transmits really easily.
Host Amber Smith: How long after someone is infected will they develop symptoms?
Jana Shaw, MD: So, there are two terms that we use. One of them is incubation period, essentially a period between exposure and development of symptoms. And for measles it can be anywhere from one to three weeks. So let's say you are exposed to someone with measles, you are not vaccinated. You can expect developing symptoms between one to three weeks.
Host Amber Smith: So that's a wide window where you could be infecting other people.
Jana Shaw, MD: Yes, absolutely. There is a slight difference between the incubation period, which is what I just described, and also your ability to transmit, which usually happens four days before the onset of rash, which is pretty characteristic and follows four days after the rash appearance. So there's probably eight days of a window, four days before you really have any symptoms, and four days after the rash onset where you are highly contagious.
Host Amber Smith: Now you said that humans are the only host. Does that mean that dogs and cats or other animals can't spread it?
Jana Shaw, MD: Correct. Typically, pets do not spread measles.
Measles is a human virus transmitted by humans, infects humans. So pets would be an unlikely source of measles infection.
Host Amber Smith: Now, I've read that during this outbreak in Ohio, about a third, I think, of the children infected have been hospitalized. So it makes me wonder, how deadly is measles?
Jana Shaw, MD: Measles is a serious virus. And you know, before we had a safe and effective vaccine, essentially 3 million to 4 million people were diagnosed with measles every year, and the majority of them would be young children. And among those who were diagnosed, as many as 10 out of 100 would develop ear infection. One in 100 or more could easily develop pneumonia, severe diarrhea, and many would end up hospitalized for those complications, including children who would end up in the hospital and subsequently die. About one in 1,000 children with measles will die from measles or will go on developing a very serious and debilitating neurological complication and infection known as encephalitis.
Host Amber Smith: And why is measles a special concern for pregnant women?
Jana Shaw, MD: Measles is a concern for pregnant women mostly because pregnant women are vulnerable to infections in general. Influenza, for example, can be severe in pregnant women. COVID was more severe in pregnant women. Measles is more severe as well because the women, during pregnancy, their body goes through a number of changes. Measles is a respiratory virus, so pneumonias can be particularly challenging for women. And their immune system is also going through adjustments. So, a combination of those physiological changes along with the aggressiveness and severity of the measles virus is particularly concerning for pregnant women. And the infection led to preterm birth, death in mothers and also complications, other complications, during pregnancy.
Host Amber Smith: This is Upstate's "The Informed Patient" podcast. I'm your host, Amber Smith. I'm talking with Dr. Jana Shaw. She's a pediatric infectious disease specialist at Upstate, and our topic today is the growing concern about measles.
Now, Dr. Shaw, can you explain how a measles vaccine was developed and what year it was first available in the U.S.?
Jana Shaw, MD: Of course, yes. So measles vaccine has been available in the U.S. since the early '60s. Initially, there was what we call monovalent measles vaccine, which means there was just measles with a single-component vaccine. The virus was killed. But subsequently we have developed a safe and also effective vaccine that more resembled the live virus known as a live attenuated (weakened) vaccine. The killed vaccine was replaced with this live attenuated vaccine.
The advantage of using that vaccine is that that vaccine more closely resembles the natural infection without causing the serious disease. So the live attenuated measles vaccine was used for an extended period of time, but over time, in order to ease the administration and provide a better coverage for other vaccine preventable-diseases, such as mumps and rubella, which are two other common and serious infections in childhood, those vaccines were combined into one known as MMR -- measles, mumps and rubella vaccine. And later on, Merck (a pharmaceutical company) was able to also add a varicella component to it, which is the chickenpox.
So we also have MMRV vaccine that is reserved for older children, mostly because there are just higher rates of fever following that vaccination. But currently there are two types of measles-containing vaccine available in the U.S. One of them is MMR, and the other one is MMRV. Both are very effective, very safe.
Host Amber Smith: You were telling us how the vaccines are combined -- measles, mumps, rubella, chickenpox. Rubella is like measles, right?
Jana Shaw, MD: Rubella is slightly different. It can look like measles, yes. So rubella is an infection that presents with fever and with rash. You can see conjunctivitis (pink eye). It's usually not as severe as measles for children. But the problem is that when pregnant women are infected with rubella virus, those babies, those fetuses will go on developing congenital rubella syndrome, which is very damaging. Those babies are impaired. Many may not survive. So, the No. 1 reason why we introduced rubella component into the MMR vaccine is to prevent congenital rubella syndrome.
Host Amber Smith: And then mumps. We don't hear much about mumps, but is that still a threat?
Jana Shaw, MD: Mumps continues to be a threat. Mumps is particularly concerning for its infection of testes because we see inflammation of male genitalia that can subsequently lead to infertility. Mumps can also, outside the swelling of the parotid gland, can also cause CNS, or central nervous system, infection, known as encephalitis or brain inflammation, and can cause joint problems as well. So mumps, although it appears to be milder, may have a more significant impact when it comes to male infertility.
Host Amber Smith: Now childhood vaccination -- does that provide lifelong immunity?
Jana Shaw, MD: Childhood vaccination with two doses of the measles-containing vaccine will provide a lifelong protection. Correct.
Host Amber Smith: And if someone's parents did not get them vaccinated as a child, and they're an adult now, can they get vaccinated and get that lifelong immunity?
Jana Shaw, MD: Yes, they can. You know, any individual who thinks they are not immune to measles either because they have not received a vaccine or they were born close to the period when measles stopped circulating and they were not vaccinated, they should check with their (medical) provider. They can have their titers checked (a blood test for immunity), and if they're not immune, they should get vaccinated.
Host Amber Smith: If someone had measles and survived, do they then have protection from getting it again?
Jana Shaw, MD: Yes, they do. Natural infection itself is protective and provides lifelong protection as well.
Host Amber Smith: Now, a few years ago there was kind of a fear about measles vaccine in particular that dissuaded some people from getting vaccinated. Are you still seeing that there's a segment that don't want to be vaccinated?
Jana Shaw, MD: Yes, unfortunately we have seen a rise in vaccine hesitancy, and in fact WHO (World Health Organization) has declared it as a top 10 threat to human health in 2019. So, vaccine hesitancy/vaccine refusal is a major public health problem. And, it does not stop with flu vaccines or COVID vaccines. We have also seen issues with vaccine uptake when it comes to measles.
Host Amber Smith: Well, I'd like to go over the symptoms of measles, the things that parents maybe should be on the lookout for. But fevers, coughs, runny noses, those are so common in children. Is there something that stands out about those symptoms for measles?
Jana Shaw, MD: For a person who has seen measles, it's pretty characteristic when you see a child with measles. I had the privilege to care for a child with measles when I was in medical school. So for me, I'll never, never forget that. There are some characteristic features that make measles stand out, such as the child has a runny nose, children are miserable, they have a cough, they have characteristic pink eyes. And they have a rash that typically starts on top of the body, starts on the head, on the face, and spreads down throughout the body.
The rash is somewhat characteristic. It actually has morbilliform appearance, which means it's red, it's flat, but it can become bumpy. And, once you see the constellation of the symptoms along with understanding the tempo as those signs and symptoms develop, one cannot forget about measles. Fever is a common symptom as well.
On the other hand, there are a number of other infections that we see during childhood that can mimic or mask or look like measles, and those are times when it can be particularly challenging to diagnose measles or think of measles if one really is not tuned in to that condition. And because most of the providers nowadays have not seen measles, it's understandable that they will not think of it. So, a really, really important point for both parents and providers to remember: always check the vaccination status. If your child is not vaccinated, please remind the provider who's taking care of your child that your child has not received measles vaccine, so proper steps can be taken to take care of your child.
Host Amber Smith: Is there a specific treatment for a child who has measles, at home?
Jana Shaw, MD: We really don't have any specific therapy. We use what we call supportive care. So we help the children to get through the infection, especially those who end up seriously ill, end up in the hospital with pneumonia, severe diarrhea, let's say. We provide oxygen, fluids. Vitamin A has been used, particularly in developing countries where malnutrition is common, to assist in mitigation of some of the seriousness of measles infection. But it's really not much more that one can do once children are infected and end up seriously ill.
Host Amber Smith: Well, before we wrap up, I'd like to make sure everyone understands what herd immunity is, tied together with the measles outbreaks. Why is herd immunity important?
Jana Shaw, MD: Herd immunity, or what we prefer to call community immunity, is really important because it allows protection of those who cannot be safely vaccinated because they are ill with cancer, or they're too young to be vaccinated, and in measles it means children less than 12 months of age. So the community immunity protects those people because there is enough immunity that does not allow the virus to enter and spread.
When we think of vaccine-preventable diseases, we really need to think of them at a local level because national- or state-level data, when you look at vaccination coverage, can be misleading, because if most communities vaccinate, the state-level vaccination data will look encouraging and reassuring. However, we do have small communities where most of the children are not vaccinated, and those would be communities at risk for introduction and spread of measles.
We also need to remember that although vaccines, especially measles vaccines, work really well, they are not perfect. Even fully vaccinated people may not respond and may not be protected. So in communities where even if you have a high level of coverage, there will be number of individuals who may be vulnerable to measles. So again, keeping that community immunity at the highest level possible is key to prevent future outbreaks.
Host Amber Smith: So if there's a classroom with 30 children, and 29 are vaccinated, and the one unvaccinated child contracts measles, those 29 classmates or their families could be at risk because no vaccine is 100% effective?
Jana Shaw, MD: So there could be. The risk will be very low, considering that we know that two doses of the vaccine leaves the majority of the children protected. So you are correct. There is still a small risk of others being at risk. And actually our own research showed that if you live in a community with high vaccination coverage, you are unlikely to introduce and spread vaccine-preventable diseases, such as pertussis (whooping cough) and measles. But if you live in a community where the vaccination coverage is low, in other words, people are not getting their children vaccinated, even if you are vaccinated, you are at increased risk for those infections because no vaccine is 100% perfect.
So again, be mindful. Remember where you live. Inquire, if your child is at school, inquire about your school's vaccination coverage and, if possible at all, get your child vaccinated to reduce risk of vaccine-preventable infections, such as measles.
Host Amber Smith: Well, I appreciate you making time for this interview and sharing this information, Dr. Shaw.
Jana Shaw, MD: Thank you, Amber. Thank you for having me.
Host Amber Smith: My guest has been pediatric infectious
Dr. Jana Shaw. She's a professor of pediatrics and of public health and preventive medicine at Upstate. "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. Find our archive of previous episodes at upstate.edu/informed.
This is your host, Amber Smith, thanking you for listening.