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How many measles cases in 2025? Is there a blood test for Alzheimer's? Is the shingles vaccine safe? Does the shingles vaccine prevent dementia?
AMA's Vice President of Science, Medicine and Public Health, Andrea Garcia, JD, MPH, covers measles outbreak news, a new blood test for Alzheimer's disease, the latest trends in childhood vaccination rates, and how the shingles vaccine helps prevent dementia. AMA Chief Experience Officer Todd Unger hosts.
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Speaker
- Andrea Garcia, JD, MPH, vice president, science, medicine & public health, American Medical Association
Transcript
Garcia: Cases are on the rise all across the country too. According to the CDC, in 2024 there were over 35,000 cases of pertussis. It's the highest number in more than a decade.
Unger: Hello and welcome to the AMA Update video and podcast. Today is our weekly look at the public health issues facing physicians and patients across the country with the AMA's Vice President of Science, Medicine and Public Health, Andrea Garcia. I'm Todd Unger, AMA's chief experience officer. Welcome back, Andrea.
Garcia: Thanks. Always good to be here.
Unger: Well, let's start the week off with some bad news, development in the ongoing measles outbreak in Texas. Andrea, can you bring us up to speed on that?
Garcia: Sure, Todd. And unfortunately, we learned a few days ago that a second child in Texas has died as a result of this measles outbreak. The patient was an eight-year-old girl who died of measles pulmonary failure at a hospital in Lubbock, Texas. This child was reportedly unvaccinated and had no underlying health conditions.
As I'm sure you recall, the first death in this outbreak occurred back in February. It was also of a school-aged child in Texas who was unvaccinated. And then in March, we heard about an adult who was unvaccinated who died in New Mexico after testing positive for measles. In that case, the official cause of death is still under investigation.
And it's tragic to hear about these losses, especially because they are preventable. And we know the most effective way to prevent measles is the MMR vaccine.
Unger: That's right. It is very sad news and preventable. Andrea, what is the rest of the story with the latest case counts?
Garcia: Todd, we're still continuing to see a number of new measles cases across multiple states. As of last Friday, the number of cases in Texas had risen to 481, which is up from 400 the week before. In New Mexico, there are now 54 cases. That's up from 42 when we last talked.
There's also been a new case in Oklahoma, which brings the total number of confirmed cases there to eight. They also have two probable cases. As for Kansas, last Wednesday, there was one new case since we last talked, which brings the total number of cases there up to 24.
As we've discussed, these states aren't the only places where we're seeing measles outbreaks. If we look at the CDC data, there have been 607 measles cases in the U.S. so far this year. That is more than double the number of cases we saw in all of 2024.
Unger: Jeez, Andrea. I just remember, gosh, it seems like a few weeks ago when those numbers were in the double digits and now over 600. So that definitely brings some different kind of perspective in to the story.
Let's switch gears here and go to a different big story about something we haven't talked about in a while, and that's shingles. And this in particular is about a new positive benefit of the shingles vaccine. Andrea, tell us more about that.
Garcia: Well, there was a new large study that has found that getting vaccinated against shingles reduces the risk of developing dementia. This study was published in Nature, and it found that people who got the shingles vaccine were 20% less likely to develop dementia in the next seven years than those who were not vaccinated. From a public health perspective, 20% is a significant reduction. It's even more notable because right now we don't really have many other ways to slow down the onset of dementia.
Unger: That's well said. 20%, that's huge in public health terms. Andrea, any theories as to why the shingles vaccine also happens to help with dementia?
Garcia: Well, there are a few, and one is that the vaccine reduces the neuroinflammation caused by the reactivation of the shingles virus and inflammation can contribute to many long-term illnesses, including dementia. So reducing reactivations and the inflammation associated with them may help protect against dementia.
Another possibility is that the vaccine triggers a broader response from the immune system, and a more reactive immune system provides greater protection against dementia. But we're going to need more research to really understand this connection. Still, this is a promising development, and it provides yet another reason for people to get that shingles vaccine.
Unger: And good to have a piece of good news in a sea of otherwise sometimes bad news. How about another piece of good news in this time also related to brain health? There's a new blood test for Alzheimer's that was driving headlines last week. Andrea, what's the story there?
Garcia: Well, there have been a lot of developments around Alzheimer's lately, and this one is especially interesting. Right now, if a physician thinks a patient might have Alzheimer's, they can order a blood test to see if a patient's brain contains sticky amyloid plaques, which are a hallmark of the disease.
However, this test doesn't tell physicians how far the condition has progressed, and this new test does just that. It tracks the level of protein called MTBR-tau243. This protein is linked to toxic tau tangles that build up in the brain as a part of Alzheimer's. So this test can not only help to diagnose Alzheimer's, but it can also help distinguish between stages of the disease. And it can help identify patients who have cognitive decline caused by something other than Alzheimer's.
Unger: Andrea, if I remember correctly, was there not another test for Alzheimer's that a lot of people were talking about last year?
Garcia: Yeah, that was back in July, and there was a study published in JAMA® about an Alzheimer's blood test. And this test measures a protein called plasma phosphorylated tau 217 or p-Tau217 for short. And this protein is different from the one that's measured by the test we just discussed. But both of these tests are aiming to do something similar, which is more accurately diagnose Alzheimer's and understand how the condition has progressed, with hopes that in the future, when tests like these are widely available, patients will not only be able to get diagnosed with Alzheimer's earlier but also receive more targeted treatment based on the stage of their condition.
Unger: OK. Well, thank you so much for that update. Also in the news last week was a condition we haven't talked about in a while, and that is whooping cough. Andrea, what do we need to know about that?
Garcia: Well, whooping cough, which is clinically called pertussis, was making headlines due to an update from the Louisiana Department of Health at the end of March. The department said that so far this year there have already been 110 cases of pertussis in Louisiana. And for some context, in all of 2025, there were 154 cases. So, this is definitely a concerning trend.
Additionally, the department confirmed that two infants have died of pertussis in the last six months. So as a part of this update, the department underscored the importance of being vaccinated against pertussis and that the best way to protect newborns is to get that Tdap vaccine during pregnancy.
Unger: Now, you mentioned this was out of Louisiana. Are we seeing pertussis cases increasing in other states?
Garcia: Yeah, cases are on the rise all across the country too. According to the CDC, in 2024, there were over 35,000 cases of pertussis. It's the highest number in more than a decade. In the few years prior to the pandemic, for example, we were seeing roughly between 15,000 and 19,000 cases. So, like in Louisiana, this rise in cases nationwide is something to keep an eye on and to be concerned about.
Unger: It's kind of not possible to compare what we're seeing now with the measles outbreak with what you're talking about right now. Is the increase that we're seeing emanating from the same problem?
Garcia: Well, Todd, like with the measles outbreak that started in Texas, a decline in people getting vaccinated is a major contributor here as well. A study in the CDC's MMWR back in October really looked at this and helped to put this decline into perspective. That study looked at vaccination trends among children in kindergarten.
It found that from the 2019 to 2020 school year to the 2022-23 school year, vaccinations overall declined from 95% to 93%. But specifically, for the DTaP vaccine, the vaccination rate for the '23-24 school year was 92.3%. And while this is still high, the fact that we are seeing a decline is definitely not encouraging.
Unger: All right, Andrea. We'll definitely keep an eye on those numbers as well. If you found this discussion valuable, you can support more programming like it by becoming an AMA member at ama-assn.org/joinnow. patients can get involved by joining the AMA's Patient Action Network at patientsactionnetwork.com. As always, you can find all our videos and podcasts at ama-assn.org/podcasts. Thanks for joining us today. Please take care.
Disclaimer: The viewpoints expressed in this podcast are those of the participants and/or do not necessarily reflect the views and policies of the AMA.
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