A Decade after Disneyland

Ten Years Ago Today, California Pushed Back on the Anti-Vaccine Movement. Now, RFK Jr. Runs HHS. A Look at Networked Activism and The Future of Public Health.

Nick Ansell/PA Wire/ZUMA

Ten years ago, a measles outbreak at Disneyland sickened 125 people – a quarter of them under 5 years old. Nearly 20% were hospitalized. Fortunately, no one died. This happened as California was emerging from its worst whooping cough epidemic in 70 years. At the time, I was a new mom, a recent transplant from New York who was researching San Francisco preschools – and wondering why California made it so easy to opt kids out of polio vaccines for kindergarten. 

My son had just turned one. He’d had his first MMR shot; full protection requires two. According to antivax math, that’s six vaccines. They count each component of a combined shot to inflate the tally — part of a longstanding scare tactic: “76 vaccines before age 18!” Alongside that came ominous warnings about “chemical” ingredients and debunked claims linking vaccines to SIDS, autism, and allergies.  As a new parent on Facebook, I saw a steady stream of this propaganda from groups like Children’s Health Defense. It was pushed to me by recommendation engines and targeted ads. CHD’s chairman featured prominently: “Spend a Day with Robert F. Kennedy Jr. and Learn the Art of Falconry,” one fundraiser teased. 

Today, RFK Jr. is the U.S. Secretary of Health and Human Services, spreading antivax math in official Fox News appearances and making debunked claims centerpieces of America’s health policy. The “do your own research” crowd is doing research for all of us now, complete with AI-generated citations and misinterpreted studies. Over the past decade, the anti-vaccine movement has gone from harassing pediatricians in comment sections to setting federal policy. Their rise is the story of a movement that understood how to leverage influencers, algorithms, and networked crowds to achieve political power – while systematically eroding trust in expertise. It’s also a story of what public health failed to see coming. 

But ten years ago today in California, for a moment, things looked like they might go in a different direction — because in the fight to change school vaccination policy after the Disneyland measles outbreak, the anti-vaccine movement actually lost.

By the early 2010s, antivaxxers had already mastered social media. Blogs and Facebook groups let them bypass media gatekeepers who’d stopped covering vaccines-cause-autism claims. Social media proved ideal for viral storytelling in which true believers served as amplifiers. Questioning expertise became a profitable form of rebellion for a growing group of wellness influencers, who formed tight bonds with their audiences. By 2012 numerous studies documented how well-adapted the movement was to the medium. The themes weren’t new — for as long as there have been vaccines, there have been “anti-vaccination leagues” tapping into fears about bodily autonomy and government overreach. But now the persuasive messages came from mothers at kitchen tables sharing relatable, sometimes heartbreaking stories that made others think, “This could be me.” 

Even as a pro-vaccine parent familiar with safety data and how the rhetoric functioned, the steady drumbeat of tragedy and rumor was unsettling. Once you joined a few Facebook groups, the content dominated your feed; within the communities, there was nothing to counter the claims. On Twitter, high-output antivax accounts dominated vaccine conversations, creating a majority illusion. Pro-vaccine parents simply vaccinated their kids and moved on; they weren’t tweeting about it. The asymmetry of passion was self-reinforcing.

The CDC and public health institutions, meanwhile, were largely absent from the discourse. Their content — dry fact sheets and PDFs — couldn’t compete with relatable influencer videos calling audiences to action. This mismatch would persist, rather notoriously, through COVID…

But the Disneyland measles outbreak briefly created an outpouring of strong pro-vaccine sentiment among ordinary people. Suddenly, the risk of not vaccinating was clear, and the public was annoyed: why was measles back in California in 2015?  When Sacramento senator Richard Pan introduced legislation to strengthen vaccine requirements for California schools by removing the “personal belief” exemption, the bill polled well. But the explosion of incandescent rage on social media gave the opposite impression.

Antivaxxers mobilized instantly. California groups linked up with activists in Texas and Maine to start dominating the online conversation. There was no comparable pro-vax infrastructure; I wanted to help but didn’t know how. I called Pan’s office and his staffers pointed me to some other moms who’d also reached out. We decided to launch a social media group called Vaccinate California. We posted on social media, encouraging calls to legislators. We studied the opposition tactics and messages, and worked to grow a countermovement. But we found the social media platforms fairly stacked against us: ad-targeting tools only surfaced anti-vaccine keywords, and maintaining positivity did not seem to win many points with the algorithms. So we also participated in the occasional dunking and meme baiting that drove the Twitter attention machine — I got blocked by Rob Schneider and Andrew Wakefield (I regret nothing). As the antivaxxers lost votes in committee hearing after committee hearing, however, things got increasingly toxic. Some of the legislators and advocates started receiving threats; this was just after Gamergate, and online mobs had realized intimidation was a strategy. Watching Senator Bill Cassidy vote to confirm Robert F. Kennedy Jr years later, despite his disastrous confirmation hearing, reminded me of just how nasty things had gotten. 

Kennedy had also showed up in California ten years ago. He screened Trace Amounts, a film about mercury in vaccines, and started tossing around the phrase “a holocaust” to describe autism: “The autism holocaust has permanently consumed 1 million children in this country.” He recruited the Nation of Islam into the fight, telling Louis Farrakhan that the MMR vaccine had been genetically modified to attack Black and Latino boys and that the CDC — an organization he now leads — was complicit. (He would later disavow Farrakhan while running for president.)

SB-277 was signed into law by Governor Jerry Brown on June 30, 2015. It passed not because of internet activism, but in spite of it. We had created a visible presence in support of the bill, but ultimately a bipartisan coalition of legislators had decided to trust a combination of polling and science over online rage. Still, I felt that I’d just lived the future of shaping public opinion — that every policy battle going forward would be similarly fought, with influencers, factions, memes, bots, and trolls…and possibly a sizeable helping of harassment. 

The California vaccine fight of 2015 previewed the information landscape we now live in, where influence is decoupled from expertise, trust flows through creators, and participatory networked activism is no longer optional for those who care about truth.

What I think about most often today, ten years later, isn’t the bill’s passage, but two failures that happened soon after. The first was that no one in the vaccine advocacy space seemed able to get the CDC to take this shift seriously. No one there seemed alarmed by the rising conspiracy theories or the growing online mobilization against vaccines. “Those are just some people online,” one person said to me at a conference when I asked why they didn’t start speaking up, countering the anti-vaccine movement, being in the conversation.

The second failure was infrastructure. Vaccinate California couldn’t find a way to fund a pro-vaccine parent movement, so it stopped operating. There was no falconry day with a Kennedy to raffle off. We declined a pharmaceutical company grant because we were concerned about independent credibility, but anti-vaxxers called us “pharma shills” anyway.

Between 2015 and 2020, influencer culture professionalized, and trust in institutions fractured. Wellness gurus, political influencers, and antivax creators built followings through relentless content loops. Meanwhile, public institutions stuck with PDFs. By the time COVID hit, the authenticity gap was vast—and the anti-vaccine movement was ready. In January 2020 — before the virus was widespread, and long before a COVID vaccine existed — antivax activists were live-streaming strategies for using the pandemic to undermine vaccines writ large. The backlash to COVID vaccination was not spontaneous, and it was not surprising. The anti-vaccine movement managed to successfully cement vaccine refusal as a right-wing identity marker. That shift will be very difficult to undo. 

Shared reality has fractured, and real-world consequences no longer seem to sway public opinion. There is currently a measles outbreak happening today, in west Texas. There have been 750 cases since January, with a majority occurring among those who are unvaccinated (or whose status is unknown). 219 cases in kids under four years old.

This time, two children have died.  

In response, the United States Secretary of Health and Human Services has chosen to weaken American vaccination policy. This would be odd but for the fact that he is an antivaxxer, something that was glaringly obvious to everyone including Senate Republicans, who knew better and confirmed him anyway. And so, in the last few weeks, RFK Jr. fired all 17 members of the CDC's Advisory Committee on Immunization Practices (ACIP) and named a pantheon of conspiracy theorists and the dubiously qualified to replace them; withdrew the United States from Global Alliance for Vaccines and Immunization (GAVI) due to purported concerns about “vaccine safety” (a decision that may cause many deaths); and unilaterally made decisions to change COVID-19 vaccine recommendations for pregnant women and children. 

Ten years after California strengthened its vaccine laws, a lunatic is running the asylum — and while most Americans still vaccinate their children, their voices have been largely absent from the online spaces where public perception is shaped. 

That needs to change. Groups like the American Academy of Pediatrics are stepping up to counter Kennedy’s ACIP, and they need support and amplification. A wave of physician and public health creators are now on the socials making really fantastic content to counter the nonsense — even the kind now coming from federal agencies. Follow them. Share them with people who are looking for information. And speak up or organize yourself – before you have to scramble because of a legislative fight in your state. There’s no reason the label “warrior mom” (or dad) should belong to those bringing back nearly-eradicated diseases. Reclaim the frame. Making America healthy again includes measles and polio vaccines for kindergarten. It really is that simple.

The Disneyland outbreak jolted California into action. But after a pandemic that killed over a million Americans, the political will to protect children through basic immunization policy has evaporated. Institutions won’t fix this — the CDC is not in a position to at the moment. Social platforms won’t fix it. Fact-checks and good information are important — but they won’t fix it, either.

What will? The same tactics that brought us here — storytelling, participation, networked community-building — can be used to fight back, grounded in evidence but fluent in the dynamics of communicating with people. The anti-vax movement has a head start. But they don’t have a monopoly. It’s time for the silent majority to get back in the game — not just to defend public health, but to define it.