When (and how) do we debate vaccine science?

This is a collaborative post with Dr. Katelyn Jetelina who writes the newsletter Your Local Epidemiologist. The post originally appeared on her substack here.

Over the weekend, a vaccine brawl took place. Robert F. Kennedy, Jr.—presidential candidate and longtime spreader of old, tired vaccine rumors— had a conversation with Joe Rogan on his podcast. The conversation bled onto social media in which Rogan ultimately challenged Dr. Peter Hotez—a Nobel Prize-nominated vaccine scientist—to debate RFK Jr. about vaccine rumors that have already been addressed dozens of times.

Everyone chimed in: from Elon Musk amplifying the conversation to Mark Cuban calling Rogan a bully to stalkers confronting Hotez at his house and pressuring him to debate. 

Through the noise, Hotez held his ground; he didn’t go for the bait. He’s not going to debate. But he did propose an alternative: he will go on Rogan’s show to talk about vaccines but without RFK Jr.

Hotez 100% made the right move.

This is why. (Brought to you from our experience in the trenches.)

The dilemma

There is no doubt that rumors and falsehoods on social media impact behavior. As a scientist, it’s really tempting to address them because we are deeply entrenched in the data. We can help, right?

But the toughest part of addressing these rumors is deciding when to actually do it. There are benefits but also great risks:

• It can create a false sense of equivalence. When scientific experts debate those promoting fringe, demonstrably false views, it can create a false impression of a genuine scientific controversy where none exists, misleading the public.
• Backfire effect. It’s very easy for these discussions to get heated, which can lead to psychological defense mechanisms being triggered, making it even more challenging for people to learn. People don’t think as logically when they’re angry or insulted.
• It takes a lot of time. “A lie can go around the world before the truth gets its pants on.” Scientists’ time and energy are finite, and many scientists who address these rumors volunteer their free time to do so. Choosing which debates are worth the time is important.
• May be personally dangerous. Presenting yourself to a hostile audience can become physically dangerous. A close scientist friend of YLE pushed against Rogan during the pandemic, and their family had to flee after the FBI picked up death threats.

Live debate rewards charm, not data

We understand why live debates are preferred by many—they are more accessible and more entertaining than the slow work of careful science.

While scientists are great professional arguers (in fact, debate is ingrained into the definition of science), scientific debate is not usually done in the same way as political debate between candidates vying for your vote or high school debate teams.

Instead, scientific debate is typically done in writing and focuses on very specific scientific questions. This allows for careful presentation of data and citation of sources. It can be slow and boring, but it is much more effective.

Live debates can easily be hijacked when arguers use logical fallacies and rhetorical tricks that give the appearance of “winning,” but in reality are a path to nowhere. Both of us have experienced being on the receiving end of these types of dead-end debates:

• Moving the goalpost: As soon as one question is adequately answered with data, the goal post is moved and a new excuse is found why the answer is unsatisfactory. This is done ad nauseum so no amount of answers or data are ever deemed “enough.”

• “Firehosing”: Throwing so many different rumors at the scientist all at once that it is impossible to address them all. 

• Unfalsifiable hypotheses: Assertions that are impossible to prove wrong, not because the assertions are correct but because they are untestable. No amount of inquiry will ever lead to an answer.

• Rapid topic switching: When one claim is satisfactorily addressed, instead of acknowledging it and learning, a new topic is rapidly introduced.

• Ad hominem attacks: Instead of discussing specifics of data and scientific claims, the scientist is attacked. (Calling them a pharma shill is a particularly common one.)

• Misunderstanding standards of evidence: For a successful debate on science to occur, both parties must be in agreement about how much weight different types of evidence are given (anecdotes vs. observational trials vs. randomized-controlled trials, etc.). When one party holds an anecdote as more informative than a randomized-controlled trial, it’s very difficult to have a useful discussion.

“Debates” like these are often harmful. They don’t help people discover what’s true; they confuse and divide.

Some debates are worthwhile

How do you tell the difference?

One easy check: are participants willing to change their minds if a valid argument is presented? These folks are definitely worth the time to talk to. But if someone is repeating the same tired rumor, despite it having being studied and addressed over and over and repeatedly found to be without merit, chances are a debate with that person is not going to be particularly helpful.

Also, subject matter is important. Beyond vaccines, it’s important that the science is not politically and/or religiously polarized. One study found debating GMOs (something that hasn’t been linked to politics or religion) can change minds, for example, but a debate on evolution (which has been religiously linked) or climate change (which has been politicized) is much less effective.

Many people are genuinely seeking answers

Hundreds of thousands of people really wanted this vaccine debate. Why?

A combination of things: severe loss of trust, anger against pharma, anger against the pandemic, anger against scientists, tribalism, and some people truly have unanswered questions.

Legitimate concerns exist. In fact, the vast majority of people who have questions or doubts about vaccines don’t outright deny vaccines as beneficial. They are somewhere in the middle of the spectrum.

The continuum of vaccine hesitancy. Credit: MacDonald and the WHO SAGE Working Group on Vaccine Hesitancy.

Answering people with valid questions needs to be scientists’ priority. We need to meet them where they are, answer their questions from a place of empathy not condescension, equip trusted messengers, and anticipate concerns so we can prevent information voids that will otherwise be filled with false rumors.

The goal should always be to foster a society that values critical thinking, evidence-based reasoning, and the dissemination of accurate scientific information. In order to do this, scientists need to get our own house in order. We need to make science more accessible, entertaining, and more down to earth while still staying true to the standards of scientific integrity.  

Bottom Line

Hotez made the right call. “Debate me or you’re a coward” will not help move knowledge forward. And, typically, it will not help those in the middle whose concerns will still not be addressed. Deeply ingrained beliefs, hostile environment, and a lack of expertise makes it counterproductive and dangerous in the worst case scenario. Given our limited time and resources, we need to focus on where we can really makes a difference.

Love, YLE and KP

“Your Local Epidemiologist (YLE)” is written by Dr. Katelyn Jetelina, MPH PhD—an epidemiologist, wife, and mom of two little girls. During the day she is a senior scientific consultant to a number of organizations, including the CDC. At night she writes this newsletter. Her main goal is to “translate” the ever-evolving public health world so that people will be well equipped to make evidence-based decisions. This newsletter is free thanks to the generous support of fellow YLE community members. To support this effort, subscribe here.