RFK Jr. is not a serious person. Don't take him seriously.

Well, president-elect Trump has announced that he will nominate Robert F. Kennedy Jr. to be the Secretary of Health and Human Services (HHS), putting him in charge of most of the nation's public health and medical research.

I can't say strongly enough how unqualified RFK Jr. is for this job. He isn't qualified to come anywhere within a thousand miles of any medical or science-related issue, much less to be in charge of health policy for the whole country. Virtually everything RFK says about science is wrong–actually, it's worse than that, because he speaks with such absolutely certainty, despite being wrong, that he convinces people to take actions that end up hurting themselves. To a normal person, someone not accustomed to lying so boldly, these claims can be convincing.

Since Trump's announcement of the nomination, I've been seeing columns in major media outlets (I'm looking at you, New York Times and Washington Post) saying things like "hey, some of RFK's ideas aren't entirely wrong." 

Just. Stop. Even a broken clock is right twice a day. Don't take RFK Jr., or his nomination, seriously.

I don't want to try to list all of RFK's mistaken views, which would require a book-length column, but here are a few. Just last year he said, on the Lix Fridman podcast, that "there’s no vaccine that is safe and effective," and that the polio vaccine did more harm than good. (Both of those statements are wildly wrong.) In 2005, he wrote a long essay for Rolling Stone and Salon which claimed that thimerosal-containing vaccines cause autism (they don't), and that the government knew about it and had been covering it up:

“The story of how government health agencies colluded with Big Pharma to hide the risks of thimerosal from the public is a chilling case study of institutional arrogance, power and greed.” [quote from RFK Jr.]

The article was full of dramatic claims like this one. The only problem was, all of them were false. Rolling Stone and Salon eventually retracted the article and deleted it from their websites. 

In 2019, Kennedy visited the island nation of Samoa to spread his anti-vaccine message, sponsored in part by his anti-vaccine organization, Children's Health Defense. (The name is highly misleading.) Vaccination rates plummeted, and just a few months later a tragic measles outbreak began, causing 83 deaths and 1,867 hospitalizations. Kennedy published an article afterwards calling it a "mild measles outbreak," and in the same article claims (falsely) that vaccines themselves, rather than measles, caused the deaths.

RFK Jr. is someone who never admits he was wrong, even (or especially) when his mistakes cause the deaths of innocent children. Instead, his conspiracy-addled brain blames someone else.

And that's only a tiny sample of RFK's misinformation. He also loves raw milk, which I wrote about in 2014 and again in 2023. Raw milk sometimes contains nasty bacteria and viruses, but fortunately Louis Pasteur solved this problem in the 1860s, when he invented what we now call pasteurization. As I pointed out in my 2023 piece, bacteria just love raw milk. And you know what else is in raw milk but not pasteurized milk? Cow poop. Just don't tell this to RFK Jr. 

By writing columns saying "RFK Jr. has some good ideas" (which I won't link to, since that's just feeding the beast), media organizations are falling into a trap: they're taking RFK seriously. I'd like to ask these journalists: if Trump nominated a first-grader instead, would you write similar stories? Maybe something like "hey, this nominee has some good ideas about nutrition!" 

Don't do it. This nomination deserves ridicule and scorn, nothing more.

I've written multiple columns (both on this site and at Forbes, my former site) warning about RFK Jr. and his dangerous anti-vaccine craziness, starting with this 2014 piece where I called him out for his efforts to lobby Congress against vaccines. His primary obsession then–and he still has this obsession–was the mistaken notion that thimerosal, a harmless preservative that isn't even used in vaccines today, causes autism. This claim has been thoroughly debunked in multiple studies. 

In 2017, I wrote about "Trump's lovefest with anti-vaxxer RFK Jr." – a lovefest that apparently still continues, seven years later. That column was about Trump's promise to put RFK in charge of a commission on vaccines. Fortunately, that vaccine commission never happened, but today we face a much more dangerous threat, if RFK Jr. is confirmed as Secretary of HHS.

I've also pointed out that Kennedy is one of the "Disinformation Dozen," a group of twelve people who, as reported by the Center for Countering Digital Hate, was responsible for 65% of all the anti-vaccine disinformation online. And earlier this year I asked how he could possibly be so arrogant as to think he's qualified to be President, given that his only claims to fame are his name, which he inherited, and his anti-vaccine notoriety.

My problem with RFK Jr. is not just that he is wrong about vaccines, although that is the most immediate threat to public health. But he's also an idealogue, someone who holds onto his mistaken ideas despite mountains of contradictory evidence, and someone who simply makes up things to "prove" his points. 

And in that quote from him above, where he uses the phrase "institutional arrogance," highlights another danger: RFK Jr. is the one who is arrogant. He believes that he can substitute his own unsubstantiated beliefs for the knowledge of genuine experts, and why? Because he's a Kennedy, a man who has lived a life of great privilege, getting into Harvard as a "legacy" despite being expelled from prep school over his drug use, all the while pretending to be fighting against the system. He is too arrogant to listen to others, or to admit his mistakes.  

So no, I cannot take this nomination seriously. Children will die if RFK Jr. is put in charge of HHS. There are tens of thousands of people who are far, far more qualified than Kennedy, and I hope the Senate will refuse to confirm him. I'm not optimistic, but I hope a few Senators will look at the man's record and treat him with the scorn he deserves.

Can you use the gut microbiome to diagnose autism? I think not

Last week, the New York Times published a story claiming that we might be able to use the gut microbiome to diagnose autism. The Times story was based on a just-published scientific paper that claimed the same thing.

This report set off all my skeptical alarm bells. My initial reaction was “oh no, more bad science around autism.” For one thing, as most scientists studying autism are aware, the modern anti-vaccine movement started with a scientific paper, back in 1998, that claimed, falsely, that childhood vaccines caused autism. That paper in The Lancet was later shown to be fraudulent and was eventually retracted, but not before a huge amount of damage was done. Its lead author, Andrew Wakefield, went on to become a hero to the anti-vaccine movement, and he continues to promote anti-vaccine misinformation to this day.

The new paper (from the journal Nature Microbiology) is not making outrageous claims like that, nor was the New York Times. However, anyone claiming autism is caused by microbes in the gut should know that the notorious Lancet study was based on a hypothesis about a “leaky gut,” a hypothesis that was discredited long ago. (I don’t want to give it any credibility, but that hypothesis held that virus particles in some vaccines somehow “leaked” from the gut and made their way to the brain. It was nonsense at the time and still is.) That’s one reason why the suggestion that microbes in the gut might cause autism (or even be used to diagnose it) raises so many alarm bells.

I’ve now looked at the study, and frankly I don’t believe a word of it. Let me be clear, though: I’m not trying to prove scientifically that the study is wrong, which would require many months of effort and a much more detail than I can put into a column anyway. Fortunately, though, there’s an earlier study that did that job for me, which I’ll get to below.

However, the science behind this study is closely related to my own work, so I feel pretty comfortable offering my opinion. So what did the authors do?

Well, as the new study explains, they collected poop (”faecal samples”) from 1,627 children, some of whom had been diagnosed with autism and some who hadn’t, and they sequenced DNA from the poop. Then they looked for bacteria, viruses, and other microbes in the DNA sequence data.

That’s right: the “gut microbiome,” is really just a polite term for bacteria that live in the intestines and the colon, some of which come out in poop. Of course, some bacteria in poop might come from the food that a person ate, but mostly these are so-called gut bacteria.

I’ve been involved in many studies like this myself, so I’ve seen that these experiments yield hundreds of different species from every sample. The data sets are very complex, and a widespread problem in the field is that these data are often misinterpreted. In the Nature Microbiology paper, the authors took these very complex data sets and fed them to a machine learning program, and voila! The AI program was able to do a pretty good job (far from perfect, I should note) identifying the autistic children, based on the melange of microbes in their poop.

Right. I don’t believe any of this, as I wrote above. Why not? Well, first of all, machine learning programs are really good at telling apart two sets of subjects (such as children with and without autism) if you give them enough data. It sometimes turns out that the learning programs are keying in on irrelevant features that the scientists didn’t intend.

For example, this 2021 paper looked at over 400 studies that used machine learning to predict Covid-19, all of which had claimed some success, and found that all of the studies were essentially useless “due to methodological flaws and/or underlying biases.” Of course, the gut microbiome study wasn’t one of those, and some machine learning experiments do work, but we should be very skeptical.

Another reason for skepticism is that the new paper doesn’t even try to tell us what the machine learning models actually learned–it just treats the programs as a “black box” that we should trust.

Perhaps the biggest flaw in the study of autism and children’s gut microbiota is this: children with autism tend to be finicky eaters, and their parents try all sorts of diets in the hope that they can at least alleviate the symptoms of autism with food. There are countless websites–many of them scams, unfortunately–claiming that special diets can help these children. Why is this important? Because a special diet will alter your gut microbiome, sometimes quite significantly.

Thus even if the machine learning models in the new study are correct, the causality almost certainly goes the other way: children with autism might have a different microbiome because they’re eating different foods. Thus it’s autism that indirectly affects the microbiome. Unfortunately, both the New York Times and the scientific paper suggested the opposite.

Now on to that earlier scientific paper I mentioned above. It turns out 3 years ago, a group of researchers in Australia published a major study in the journal Cell that addressed precisely the problem I just pointed out. In that study, the scientists collected and sequenced poop from 247 children both with and without autism. They found “negligible direct associations between ASD [autism spectrum disorder] and the gut microbiome.“

On the contrary, the authors warned: “microbiome differences in ASD may reflect dietary preferences ... and we caution against claims that the microbiome has a driving role in ASD.”

In other words, three years ago a study in a major scientific journal found that there was no connection between autism and the contents of the gut microbiome. They went on to warn that if you see differences in the gut microbiome in autistic kids, those are caused by their diet, so don’t go claiming that the microbiome causes autism. The authors of the newer study, and the reporters at the New York Times, apparently decided otherwise.

So no, the gut microbiome can’t be used to diagnose autism.

A randomized controlled trial of parachutes had a surprising outcome. Anti-vaxxers, take note.

One of my themes in this column over the years has been that you need to be skeptical of many of the claims out there about science and medicine. A healthy dose of skepticism can be a good thing, especially when someone is telling you something that seems surprising.

On the other hand, anti-science forces often pretend that they too are just being skeptical, or “just asking questions,” when what they’re doing is actually science denialism. Denialism is what someone is doing when the science is basically settled, but they refuse to accept it.

Let’s consider perhaps the clearest example of denialism, and the one that causes the most harm to public health: vaccine denialism. The anti-vaccine movement, which has grown alarmingly fast during the Covid-19 pandemic, insists that vaccines don’t save lives, and even more they insist that vaccines cause neurological damage. The latter claim is a favorite of Robert F. Kennedy Jr., as he’s proclaimed in multiple books and articles, and of his VP running mate Nicole Shanahan as well.

The claim that vaccines cause autism was first promoted in a bogus 1998 article in The Lancet by Andrew Wakefield. That article was later shown to be fraudulent, and the journal retracted it, but not before it spawned the modern anti-vaccine movement and made Wakefield one of their heroes. I’ve written many columns on this topic, and others have written far more, but the movement persists.

Scientists and doctors have pointed out, over and over again, that vaccines have saved millions of lives, and are one of the greatest medical advances in the history of civilization. The rapid development of the Covid-19 vaccine was a triumph, and it undoubtedly saved tens of millions more lives.

In defending their denialism, anti-vaxxers frequently ask this question: “where are the randomized controlled trials for vaccines?” They imply that scientists haven’t run such trials because they (the scientists) know that vaccines don’t really work.

That’s nonsense, of course. Scientists have conducted hundreds of studies, involving millions of people, showing how vaccines prevent disease and death.

But we don’t have any randomized controlled trials for childhood vaccines, and we never will, for an obvious reason: it would be deeply unethical. Let me explain.

A randomized control trial (an RCT) works like this: first, you identify a large group of people whom you want to treat, say by giving them vaccines. Then you divide them at random into two groups: the treatment group, who get the vaccine, and the control group, who get nothing. To prevent bias, you might also “blind” the subjects and experimenters so that no one knows who’s getting treated. For example, you could use shots filled with saline solution for the control group, so they think they’re getting a vaccine.

Once you’ve administered the treatment, you follow everyone for some period of time and see who does better. If the treatment group does better, then we say that the treatment worked.

Obviously, we cannot run an RCT for childhood vaccines, because withholding vaccines from children could grievously harm or even kill them. Instead, we can use data collected over time from millions of children, some of them vaccinated and some not, and measure vaccines’ effects from that. It’s not perfect, but these observational data show overwhelming evidence that vaccines for diseases including measles, mumps, rubella, polio, and smallpox are incredibly effective.

Yet anti-vaccine activists continue to call for RCTs, and they pretend that scientists who point out what I just wrote are not to be trusted.

Now to those parachutes in the title of this piece. We know that parachutes work, right? And yet where are the randomized controlled trials? Maybe we shouldn’t use parachutes until some scientists conduct that study? Hmm.

Well, if you’re thinking of skydiving and wondering about this question, you’re in luck! Because a few years ago, a group of scientists at Harvard, UCLA, and the University of Michigan ran an RCT on parachutes! And they published it, too, in the highly regarded British Medical Journal, now called BMJ.

I’m sure you’re curious about how they did this study, and how it turned out. Well, I’m going to tell you.

It was a small study: they approached 92 aircraft passengers and enrolled just 23 people. They randomized them into two groups, with 12 people wearing parachutes and 11 jumping with just an empty backpack.

What happened? Amazingly, there was no difference! Also amazingly, no one died! How could that be?

Well, reading the details of this (ahem) well-executed study, one learns that “randomized participants ... could have been at lower risk of death or major trauma because they jumped from an average altitude of 0.6 m on aircraft moving at an average of 0 km/h.”

In other words, participants did jump from a plane, but they were jumping from less than a meter off the ground and the plane wasn’t moving. A figure from the study illustrates the experiment:

Representative study participant jumping from aircraft with an empty backpack. This individual did ... [+]

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So as you see, this particular RCT of parachute use didn’t prove anything. Even so, the authors note, tongue in cheek, that “Beliefs grounded in biological plausibility and expert opinion have been proven wrong by subsequent rigorous randomized evaluations. The PARACHUTE trial represents one more such historic moment.”

In case you’re wondering how on earth the BMJ would publish a study like this, I can explain that the date of publication was Christmas 2018. The BMJ has a long tradition of publishing satirical but seemingly serious articles on Christmas, and this was a particularly good one.

On the other hand, though, my larger (and serious) point is that the public shouldn’t lose trust in science. Even when science gets things wrong–and it does–it’s still the best toolkit we have for figuring out whether or not something works, or is true. The recently popular cultural trope that truth is malleable, and that each person can choose their own “facts,” is dangerous. When it comes to scientific facts, that’s just wrong.

Parachutes work, and not using them would be exceedingly risky. Vaccines aren’t quite as guaranteed as parachutes, but they come pretty close.

RFK Jr. is a famous anti-vaxxer. How does this make him qualified for President?

I’ve written about the anti-vaccine movement and its many proponents more times than I can count. So why write about it again? Because one of them is running for President of the United States.

Robert Kennedy Jr. is famous for two things: first, he’s famous because he’s the son of a former Senator and the nephew of a former president. His father, Robert Kennedy Sr., served as Attorney General under President John Kennedy and then as a US Senator. Tragically, both JFK and RFK were assassinated in the 1960s, and RFK might very well have been elected president in 1968, as he was leading the Democratic field when he was killed.

Having a politician as one’s father does not qualify anyone for office, although many children of politicians use their famous name to win elections. That’s clearly what RFK Jr. is now hoping for.

But what RFK Jr. is really famous for now, and for the past 20 years, is something entirely different. As I wrote nearly a decade ago, Kennedy is obsessed with the notion that vaccines cause autism. He’s particularly obsessed with the thoroughly discredited idea that thimerosal, a preservative used in some vaccines, causes autism.

His efforts to convince people of the harms of vaccines landed Kennedy in the number two position on the infamous list of “The Disinformation Dozen,” This list, created by the Center for Countering Digital Hate, contains “the twelve anti-vaxxers who are responsible for almost two-thirds of anti‑vaccine content circulating on social media platforms.” Yes, this is what RFK Jr. has been focusing his energy on, at least until he decided to run for President.

Ten years ago, Kennedy published an entire book on this topic, called “Thimerosal: Let the Science Speak,” and he promoted it both in the press and in the halls of Congress. He had personal meetings with then-U.S. Senator Barbara Mikulski and Sen. Bernie Sanders to try to convince them to take action based on his claims. Why is it that a scientifically unqualified anti-vaccine advocate got a private audience with two U.S. Senators? Because he’s a Kennedy.

RFK Jr. gives hundreds of speeches a year, and up until the early 2000s, he spoke mostly on environmental issues. I heard one or two of his interviews during that era, and he was quite convincing. His usual argument was that large corporations were engaged in some kind of conspiracy to damage the environment so that they could increase their profits. That made sense to me!

But then he found the thimerosal issue and went completely off the rails. One example was a Salon.com and Rolling Stone article (jointly published in both magazines) that he wrote in 2005, which claimed not only that thimerosal-containing vaccines cause autism, but that “the government” knew about it and had been covering it up. Kennedy wrote that

“The story of how government health agencies colluded with Big Pharma to hide the risks of thimerosal from the public is a chilling case study of institutional arrogance, power and greed.” [quote from RFK Jr.]

Alarming-sounding stuff. The article was full of dramatic claims like this one. The only problem was, all of them were false.

To explain, let’s review what thimerosal is and why it has probably saved many lives. There was never a conspiracy because there was nothing to hide.

Thimerosal is a preservative that was used in many vaccines for decades. Why? Well, as I’ve explained before, early vaccines (back in the pre-WWII era) were administered from multi-dose bottles, in which bacteria would sometimes grow. In one particularly disastrous incident in 1928, 12 children in Australia died from staph infections after receiving the diptheria vaccine from the same multi-dose bottle. After the introduction of thimerosal, bacterial infections caused by vaccination virtually disappeared.

Why the panic from RFK Jr. and others about thimerosal? Well, it’s a mercury-based preservative, and RFK assumed (wrongly) that the tiny amounts of ethylmercury in vaccines caused autism or other neurological problems. One problem with this idea is that ethylmercury is very different from environmental mercury, which is called methylmercury and which can indeed be toxic. Ethylmercury is cleared from the body far more quickly–and the minuscule amounts in vaccines have never been shown to cause any harm.

But many anti-vaxxers, especially RFK Jr., have continued to spread alarming stories about vaccines (particularly through Children’s Health Defense, an organization founded by Kennedy), and a disturbing number of parents have withheld vaccines from their children because they didn’t know who to believe.

In the late 2000's, in an effort to address the concerns of anti-vaccine alarmists, a special U.S. vaccine court conducted three lengthy hearings in which the anti-vax advocates were asked to present their best cases. One of the cases focused specifically on the question: does thimerosal in vaccines cause autism? In that case, the judge concluded:

“The numerous medical studies concerning the issue of whether thimerosal causes autism, performed by medical scientists worldwide, have come down strongly against the petitioners’ contentions. Considering all of the evidence, I find that the petitioners have failed to demonstrate that thimerosal-containing vaccines can contribute to the causation of autism.”

As a lawyer, Kennedy should have been able to understand this. The science agrees with the court: in study after study, scientists found no link between thimerosal and autism or any other kind of neurological disorder. That should have been the end of the matter, but of course it wasn’t.

Furthermore, as RFK Jr knows, thimerosal was removed from childhood vaccines in the U.S. over 20 years ago, and the rate of autism diagnosis continued to rise after that. This fact alone contradicts his major claim: if thimerosal was fueling an autism epidemic, then cases should have declined after vaccines stopped including it.

What was shocking to me, the first time I heard Kennedy talk about thimerosal in vaccines, was how absolutely certain he was. He came across as a man who remained utterly convinced that vaccines cause autism, despite the mountain of evidence against him.

After RFK Jr.'s Salon article appeared, scientists responded quickly and convincingly, pointing out its numerous flaws and distortions. Salon tried to fix the problem, issuing five corrections before throwing up their hands and removing the article entirely from their website. Rolling Stone also took down the article. Salon’s editor-in-chief wrote an apology, saying

“I regret we didn’t move on this more quickly, as evidence continued to emerge debunking the vaccines and autism link. But continued revelations of the flaws and even fraud tainting the science behind the connection make taking down the story the right thing to do .”

Kennedy has steadfastly refused to admit any errors, ever. When I wrote about him in the past, his website still displayed the original Salon article, without even the small corrections that Salon.com had made. (That website, robertfkennedyjr.com, no longer exists now that he’s running for President.)

Kennedy also published another anti-vaccine book just last year, titled “Vax-Unvax: Let the Science Speak.” (In case you didn’t notice, Kennedy has zero credentials to write a book about vaccine science, but that has never slowed him down.) And in case there’s any doubt about his leanings, early in 2024 Kennedy hired Del Bigtree, a “top anti-vaccine activist,” as his campaign communications director.

By ignoring the scientific evidence that shows that thimerosal and vaccines have no link to autism, Robert Kennedy placed himself firmly in the camp of conspiracy theorists and cranks. He’s also demonstrated breathtaking arrogance. He believes that despite his lack of scientific training, he knows the truth that every scientist who’s studied this issue has missed.

Even worse, Kennedy has used his fame to spread anti-vaccine misinformation, which grew far worse during COVID. Though I doubt he will listen to me (he’s ignored everyone else), Kennedy needs to take a hard look at the harm he’s causing to defenseless children, the elderly, and cancer patients, and anyone else with a weak or compromised immune system.

When I heard Kennedy talk about environmental topics, where I agreed with him, I was impressed by his passion and his seeming command of the issues. But having heard him speak about thimerosal and vaccines, I now realize that he’s a dangerous ideologue, willing to distort the truth so thoroughly that he can’t be trusted on any topic, even ones where I agree with him. His campaign for President, although certainly doomed to fail, is likely to increase the spread of his harmful anti-vaccine tropes.

Finally, I couldn’t help but notice that the bio on RFK Jr’s campaign’s website makes no mention of his anti-vaccine activism, even though it’s been his top priority for the past 20 years, and it’s the main reason he has the visibility he has today. It does mention “his nonprofit, Children’s Health Defense” but doesn’t say that the primary work of that nonprofit is to spread scary misinformation about vaccines. I’m just guessing here, but it appears that some of his campaign advisers have decided that being a famous anti-vaxxer might not be the best qualification for President.

Update, May 28, 2024: Since this story was published on May 27, RFK Jr. has been contacted for comment.  

Vaccines Show Surprising Link To Reduced Risk Of Alzheimer’s

Well, the anti-vaccine community is not going to like this one.

A growing body of evidence, buttressed by a new report out last month, shows that people who are vaccinated have a significantly lower risk of Alzheimer’s disease.

Yes, that’s right: in addition to the obvious benefit of protecting you from infections, multiple different vaccines have now been shown, in two large studies, to be associated with fewer cases of Alzheimer’s.

How big is the effect? Well, the earlier study, published about a year ago, looked at the flu vaccine. Scientists from the University of Texas Health Science Center, led by neurologist Paul Schulz, collected data on more than 1.8 million older patients from around the U.S., of whom half had received the flu vaccine and half had not. Their average age was 74 years, and the scientists examined health records for four subsequent years to see how many developed signs of Alzheimer’s in that time.

In the vaccinated group, nearly 48,000 patients (out of 936,000) developed Alzheimer’s during the four-year follow-up period, about 5.1% of all patients. That might sound like a lot, but in the unvaccinated patients, nearly 80,000 developed Alzheimer’s. To put it another way, patients who got the flu vaccine had a 40% lower risk of Alzheimer’s, 5.1% versus 8.5%.

It appears this benefit isn’t specific to the flu vaccine, though. In the newer study published this September, the same group from the University of Texas looked at three more vaccines: the Tdap vaccine (tetanus, diphtheria, and pertussis), the shingles vaccine and the pneumococcus vaccine. They were able to collect records on 1.65 million people, among whom more than 500,000 had received one or more of the vaccines. All of the patients were over 65 years old.

Remarkably, all three of the vaccines showed similar and quite significant benefits against Alzheimer’s disease. In an eight-year follow-up period, the risk of Alzheimer’s was 30% lower (7.2% versus 10.2%) in patients who had the Tdap vaccine versus those who hadn’t. For the shingles vaccine, the reduction in risk was 25%, 8.1% versus 10.7%. And for the pneumococcal vaccine, the risk was 27% lower, 7.9% versus 10.9%.

(Note that this study looked at the older shingles vaccine. The newer one, Shingrix, has only been widely available since 2017. The scientists hypothesize that the newer vaccine, because it’s more effective against shingles, may provide even greater protection against Alzheimer’s.)

So how might this work? Is Alzheimer’s caused by an infection, and the vaccines prevent Alzheimer’s by preventing the infection? Well, the short answer is no, probably not. Although we don’t know the cause of Alzheimer’s, we don’t have any strong evidence that it’s the direct result of an infection.

Furthermore, with data showing that at least four different vaccines offer similar levels of protection against Alzheimer’s, the evidence indicates that the effect cannot be specific to the flu vaccine, or the Tdap vaccine, or with any of the other vaccines or their ingredients.

The University of Texas group that published the study speculated that vaccines might work to protect against Alzheimer’s by “long-term reprogramming of innate immune cells,” also called “trained immunity.” This hypothesis is far too complex to try to explain here–and it involves immunology, which I don’t really understand myself and which is “absurdly intricate” as science writer Ed Yong put it. So let’s just say that this is an intriguing idea that needs more research.

And for anyone who thinks that getting an infection and recovering (instead of getting vaccinated) might offer the same benefit, that doesn’t seem to work: another study looked at precisely this question and found no connection between the number of influenza infections and the risk of Alzheimer’s. So the vaccine seems to confer a benefit that the disease itself does not. (I mention this because a popular–but wrong–claim of anti-vaccine activists is that you get better immunity from infection by catching the disease and then recovering. Not a good idea.)

Also, I have to add that these studies report correlation, not causation. So even though the effects are large and significant, we don’t know for certain that vaccines do something to directly prevent Alzheimer’s. Maybe people who get vaccinated also have other behaviors that help them avoid Alzheimer’s–although the study design tried to minimize this possibility.

Vaccines have enormous, extensively documented benefits: they prevent suffering and disease, and they’ve saved countless millions of lives. And now it appears that they offer something else: a lower risk of Alzheimer’s. So if you haven’t received your boosters, now you have one more reason to get them.

Are there two sides in the vaccine debate?

Headline from a debate about vaccine hesitancy,

from December 2020.

I keep getting into debates with people about the safety and efficacy of vaccines. I’m not talking about anti-vaxxers (though I’ve encountered plenty of them), but level-headed, rational people who genuinely have doubts.

Usually their doubts about vaccines come from dubious sources, but there’s so much misinformation out there, often coming from people with the letters M.D. or Ph.D. after their names, that I can understand why it’s confusing.

So let me engage in what is sometimes called “both-sides-ism” (a disparaging term, of course) and consider, briefly, the pluses and minuses of vaccines. While I’m at it, I’ll include some points specific to the Covid-19 vaccines.

Let’s start with the pluses, shall we?

1. Vaccines are the single greatest public health innovation in the history of medicine. They’ve saved millions of lives.
2. Vaccines completely eliminated smallpox from the planet. They have nearly (but not quite, due to anti-vax resistance) eliminated polio.
3. The new mRNA vaccines for Covid-19 are remarkably effective, have very few side effects, and are easy to modify as the virus itself mutates over time.
4. Vaccines protect us so thoroughly against childhood infections that many formerly common infections–including measles, mumps, and Haemophilus influenza–have almost disappeared.
5. Child mortality from infectious has plummeted in countries with robust early childhood vaccine programs.
6. The vaccine against human papillomavirus (HPV) will prevent many thousands of cases of cervical cancer, throat cancer, and other cancers, saving lives for decades to come.
7. Vaccines train our immune system to recognize and fight off infections, in many cases stopping the infection before we even have symptoms.

I could go on, but the bottom line is that vaccines continue to save millions of lives every year. They also dramatically reduce non-fatal illnesses, sparing people a great deal of suffering as well as long-term harms caused by some infections. (For example, mumps can cause permanent hearing loss.)

Given all of these benefits, you might wonder why everyone doesn’t get every vaccine available. Well, some people do, and part of the answer is simply that we don’t have enough vaccines for everyone, and many countries lack the public health infrastructure to deliver vaccines. But there are a few very small minuses, so let’s consider the downsides of vaccines:

1. The shot (or “jab”) hurts a little bit, and your arm might be sore for a day.
2. In very rare cases with some vaccines, some people might have allergic reactions. One example is that some flu vaccines are manufactured in chicken eggs, and people with egg allergies might react to those.
3. In a few rare cases, the live polio virus vaccine has caused some people to get polio. This vaccine was discontinued in the U.S. decades ago.
4. In rare cases, some people might have an immune response to a vaccine that causes ongoing inflammation. This includes the Covid-19 vaccine. However, the risk is much smaller than the risks associated with an actual infection.

That’s pretty much it. I hope it’s clear that the pluses far outweigh the minuses, but I imagine that some people looking at this list are wondering why I didn’t include a host of other supposed harms of vaccines, such as an increased risk of autism.

That’s because vaccines don’t cause autism or any other neurological disorder, as I’ve written before. Studies involving hundreds of thousands of people have been done to investigate this possibility, starting in the early 2000s, and all of the science points the same way: vaccines do not cause autism.

This supposed risk, and others like it, are inventions of the modern anti-vaccine movement. I won’t go into the history of the anti-vax movement here (I’ve done that before, many times), except to point out that many people promoting anti-vax misinformation are making lots of money selling “cures” for problems that don’t exist in the first place.

Anti-vaxxers continue to invent new harms caused by vaccines, and spread these claims on social media. Even with no evidence whatsoever, some of these claims catch on, because - well, the Internet.

Now back to the title of this column: are there really two sides to the vaccine debate?

Well, no.

Among doctors, scientists, and public health professionals, virtually everyone agrees with my first point in the “pluses” list above. However, we all recognize that when a foreign substance (a vaccine) is injected into one’s body, it’s possible that something unexpected might happen, and we must continually monitor vaccines so that we’ll know if something goes awry.

Let me end with an analogy. Seat belts in cars have been around for decades, and they’ve prevented millions of injuries and deaths. And yet people have argued (and probably still do) that it’s possible that wearing a seat belt might cause harm, for example if the belt jams and one cannot escape a burning car after an accident. (This seems to happen all too often in movies.) Thus you can’t argue that wearing a seat belt is 100% risk-free. Even so, wearing a seat belt is a really good idea, because the benefits are so much greater than the risks.

The same is true of vaccines. There might be some very, very small risks, but the benefits vastly outweigh them. And modern vaccines are safer than ever. There’s no serious debate about that.