Intro: This is Weekly Dose of Wellness, brought to you by Memorial Care Health System. Here's Deborah Howell.

Deborah Howell (Host): Welcome to the podcast. I'm Deborah Howell. As schools reopen each year, the importance of back-to-school vaccines cannot be overstated. Today, we'll talk about the significance of vaccination for students to safeguard them from common illnesses like mumps, rubella, pertussis, and influenza, while contributing to the collective immunity necessary for public health. Our guest today is Dr. Tempe Chen, a Pediatric Infectious Disease Specialist at Memorial Care Miller Children's and Women's Hospital, Long Beach. Welcome, Dr. Chen.

Dr. Tempe Chen: Thank you so much for having me. I'm really excited to talk to you today.

Host: Me too. Let's start out with this. Can you explain the fundamental concept of how vaccines actually work?

Dr. Tempe Chen: I will try to do my best. Basically, vaccines work to prepare your immune system to fight infections, and we try to control several factors. So, we try to control the amount of bacteria or viruses that the immune system is going to see. So, we're controlling the exposure there, and we try to use the smallest amount needed to get an appropriate immune response. We also try to control the timing of when you're exposed to something, which generally is focused on making sure it's before the highest risk of complications. And we also try to control for the severity of the pathogen.

So, in general, there's four or five different vaccine methodologies. A lot of times, we're looking at what we call attenuated viruses or weakened strains of viruses. Examples of this would be measles, mumps, chicken pox, influenza. And we use viruses that aren't able to make copies of themselves in the human body as fast as the natural ones do. And this allows the immune system to develop these sort of surveillance cells we call the memory B cells, and this will allow for shorter infections with less severe symptoms once the immune system is re-exposed to whatever that virus or bacteria may be.

Unfortunately, in those cases though, people with a weakened immune system, so someone with, say, HIV or cancer that's receiving chemotherapy, they cannot benefit from these vaccines. Other vaccines include inactivated or killed viruses, so an example of that would be polio, rabies virus, or hepatitis A virus. In this case, the virus in the vaccine can't make copies of itself and it cannot cause disease, which allows those with a weakened immune system to receive these types of vaccines. And there are other vaccines that use part of the virus or part of the bacteria. And they're basically, again, weakened and they train the immune system to recognize them as foreign and protect you when you're exposed to the disease.

Host: That's probably the best explanation of how vaccines work I've ever heard in my life. Thank you so much for that. Now, what are some examples of diseases that have been significantly reduced or eradicated due to vaccinations?

Dr. Tempe Chen: We know that polio previously had been eradicated. There have been some vaccine-associated strains of polio that have emerged, and that usually is in a developing country, such as India or Africa. We were very close to eradicating measles until people stopped believing in the measles vaccine, so we do have resurgence of measles. And we've definitely seen decreased incidence of chicken pox. I remember suffering with chicken pox when I was nine years old. I was miserable, I was itchy, and I wouldn't wish that on anyone, and it's been great that kids today don't have to experience chicken pox.

Host: Hundred percent agree with you. So, this is the biggest question I'm going to ask you today. What are some common misconceptions about vaccines?

Dr. Tempe Chen: I think the number one is that people worry that vaccines cause autism. I know the original paper that was published since got retracted. And I'll tell you, you know, I actually asked Dr. James Cherry, one of the fathers of Pediatric Infectious Diseases and Vaccine Immunology, and he said, "Why don't you take a look at cell phone use and how much we're using that and whether that could be associated." I think it's a very complex issue, but I don't have any concern whatsoever that vaccines cause autism.

I know two other big misconceptions are that that preventable disease that we're trying to prevent really isn't that bad. And what I would always recommend is think about the price you pay for natural immunity. There is always a price. There's always a trade-off. And with measles, there's an entity known as SSPE, which is subacute sclerosing panencephalitis. And that can occur 20 years after your measles infection, and you can die from it and have permanent brain damage. And who wants to walk around feeling like a ticking time bomb?

The third common misconception has to do with other inactive vaccine ingredients. So, people get worried about aluminum and mercury. And it's been shown time and time again that the amounts that are in there are insufficient to cause harm, and it's important as a stabilizer for the vaccine or to optimize the immune response.

Host: And how would you dispel the myth that kids shouldn't get so many vaccines so early and the theory on spacing them out? Why do they recommend giving so many so early?

Dr. Tempe Chen: So, vaccines are most often added to the schedule based on when the infant or the child in that case is most likely to be susceptible to disease. And what we know is that a lot of times when you're younger, you're going to have a better immune response than when you're older. We have expert committees, the Advisory Committee on Immunization Practices or ACIP, which advises the Center for Disease Control or the CDC. And we also have the Committee on Infectious Diseases that advises the American Academy of Pediatrics on vaccines. They're very well knowledgeable and schooled on the four phases of vaccine development. They look at optimizing vaccine intervals, vaccine timing. They're looking at really optimizing the immune response. And if you think about it, a lot of times the first dose of vaccine just sort of primes the immune system and gets it ready. The second dose and subsequent doses are really what are aimed at boosting your immune response and making sure that you're going to be protected.

I know a lot of people have a hard time thinking about giving their child so many vaccines at once. There's concern that that's going to cause a lot of stress for the kids. But really, when you think about it, if you space out your vaccines, your making more visits to the doctor, which could actually cause more stress, and you're also increasing the chance of needle phobia. I know that with my own kid. Every time he thinks about a needle, he just gets so worried. So it's much better to kind of get it in a one and done fashion and then not have them worry, and they have more time before the next vaccine is recommended.

Host: So true. So, what are the most common vaccines recommended these days for children?

Dr. Tempe Chen: Well, there definitely are a lot, but the good news is we've vaccinated our way, in many cases, out of seeing a lot of disease. So, we have our diphtheria, tetanus, and pertussis, or DTaP. We have the Hib vaccine, or Haemophilus influenzae type B. There's the polio vaccine, known as IPV. There's the pneumococcal vaccine, which protects against ear infections and pneumonia. That's known as Prevnar. There's the measles, mumps, and rubella vaccine and the chickenpox vaccine. Those are the most common. Then, there are others that are recommended including hepatitis A, hepatitis B, human papilloma virus or HPV, and the meningitis vaccines. And then, of course, our seasonal vaccines against influenza and COVID-19.

Host: And why are vaccinations particularly important for school-aged children?

Dr. Tempe Chen: School is a place where kids are going to get exposed to germs. I like to tell parents to think of it as immune system training. It's not infrequent that my kid's coming home with a runny nose or a cough. Luckily, he's able to play through it and go to school with it as long as he doesn't have a fever. And we design the vaccine schedule so that we're protecting the kids. prior to when they're most likely to encounter the disease in question.

Host: Got it. How does herd immunity in schools protect immunocompromised children?

Dr. Tempe Chen: So remember, immunocompromised children cannot get live virus vaccines. They also may not have a very good immune response to the inactivated vaccines. So, they may not develop as robust an antibody response. By immunizing those that are around these immunocompromised children, we protect them from getting exposed to the infection by protecting those around them, because that's their biggest risk factor. When they're going to be exposed, their immune system won't be able to protect them. And we know that these diseases can really reappear very quickly among those that are susceptible to disease. So when people stopped immunizing against measles, all it took was someone to travel internationally get exposed to measles, and then bring it back.

Host: Yeah, that has to be pretty frustrating for you as a physician to see this.

Dr. Tempe Chen: It is very challenging, yes.

Host: So, what are the current challenges in maintaining high vaccination rates among school age children?

Dr. Tempe Chen: I think certainly recently it's been twofold during the COVID-19 outbreak. A lot of people didn't go see their doctors, they missed their appointments. And usually, at our well-child checks, that's when pediatricians take a look at where you are, what your vaccine status is, and if there's any vaccine that you may be missing. I know recently there's been a lot of vaccine misinformation and mistrust of the medical system. I'm willing to admit vaccines are not perfect. There are side effects, the most common being fever, local irritation, where the vaccine is given. But looking and studying this for decades, what we know is that the benefits of the protection provided by the vaccine far outweigh the potential side effects.

Host: Yeah. Maybe a day of discomfort for protection, I think that's a good trade off.

Dr. Tempe Chen: Absolutely.

Host: Now, the Centers for Disease Control and Prevention have reported that in 2024, the number of measles cases recorded in the U.S. was significantly higher than in recent years. Why might this be?

Dr. Tempe Chen: Again, I point it back to the COVID-19 outbreak. And I think there was subsequently a lot of vaccine hesitancy and refusal to vaccinate. And part of this was The public's trust in those making the vaccine recommendations. There's a lot of concern about the profit motives of pharmaceutical companies that make the vaccine.

Certainly, there is plenty of misinformation floating around. I have people sending me TikTok videos on a regular basis where I do try to dispel what I can. Really, we've done such a good job not seeing certain diseases that people forget what it's like, and they're not able to appreciate how severe the disease is that we are trying to prevent. And I can tell you right now, we don't have a vaccine against HIV. And young adults, teens, they don't know what it was like back in the 1980s, how deadly HIV was. And so, they've forgotten. And so now, they're not as worried about it. And I think that's one of the biggest things, is not really appreciating how serious the disease is that we're trying to prevent.

Host: Absolutely. Dr. Chen, what advice do you have for parents who are hesitant about vaccinating their children?

Dr. Tempe Chen: I think it's important to acknowledge that there may be some hesitancy, that there may be some. I really, really want to encourage parents to talk to your pediatrician. Talk to other parents. We do want to make sure that we are getting good, reliable sources of information. One of the greatest sites, I think, is the Children's Hospital of Philadelphia website. It's vaccine.chop.edu. That's run by Dr. Paul Offit, who is a Pediatric Infectious Disease physician like myself. He has done research on vaccines. He can talk to you about any vaccine, and I know that he personally reviews the content on that website. And it is good, reliable information that is accurate, that comes from people who understand the science of vaccines. And we want to make sure that, again, look at that information, then talk to your pediatrician afterward. And hopefully, you can come to the agreement that it is worth getting the vaccine over allowing your child to get the disease.

Host: Understood. Is there anything you'd like to add to our conversation?

Dr. Tempe Chen: I'm just hopeful that I can change a few minds, that I can let you know that it is okay to feel a little uncomfortable and to have questions. But please talk to someone who knows about vaccines, that includes your pediatrician. You can even ask to speak to a Pediatric Infectious Disease doctor. We're happy to talk to you about that. And hopefully, you'll feel more comfortable afterwards and feel confident in the decision that you make.

Host: And don't believe everything you see on TikTok.

Dr. Tempe Chen: Absolutely, absolutely. Very great advice.

Host: Well, thank you so much, Dr. Chen, for your time and expertise today. We really, really enjoyed having you on the podcast. And hopefully, we got some good information out there about vaccines.

Dr. Tempe Chen: Thank you so much for having me, Deborah.

Host: The physicians at the Infectious Disease Center at Miller Children's and Women's Hospital can offer expert advice on immunization and infectious disease prevention. Call 562-933-8660 to learn more. And for more info or to listen to a podcast of this show, please visit memorialcare.org. That's memorialcare.org. That's all for this time. I'm Deborah Howell. Have yourself a great day.