Vaccine Adverse Event Reporting System

Based on Wikipedia: Vaccine Adverse Event Reporting System

The Database That Turned a Doctor Into the Hulk

In 2005, an anesthesiologist named Jim Laidler submitted a report to a government database claiming that a vaccine had transformed him into the Incredible Hulk. The report was accepted. It sat there in the official records until someone from the agency called him to ask questions, at which point Laidler admitted he'd made the whole thing up to prove a point.

That point? The Vaccine Adverse Event Reporting System, better known by its acronym VAERS (pronounced "vairs"), will accept almost anything you tell it.

This is both the system's greatest strength and its most dangerous weakness. Understanding why requires grasping what VAERS actually is, what it was designed to do, and why the gap between its purpose and public perception has become one of the most consequential misunderstandings in modern public health.

An Early Warning System, Not a Verdict

Think of VAERS as a suggestion box for vaccine safety concerns. Anyone—doctors, nurses, patients, worried parents, personal injury lawyers—can submit a report saying that something happened after someone received a vaccine. The key phrase here is "after," not "because of."

This distinction matters enormously.

If you get vaccinated on Monday and twist your ankle on Tuesday, you could technically report that ankle twist to VAERS. The system would accept your report. It would become part of the official database. But that wouldn't mean the vaccine caused your twisted ankle. Correlation, as scientists love to remind us, is not causation.

VAERS was established in 1990 and is jointly managed by two federal agencies: the Centers for Disease Control and Prevention (commonly called the CDC) and the Food and Drug Administration (the FDA). It grew out of the National Childhood Vaccine Injury Act of 1986, which required healthcare providers to report certain events that occur after vaccination—particularly anything the vaccine manufacturer lists as a contraindication, meaning a reason not to give subsequent doses.

The system was designed as a kind of tripwire. Vaccines are tested extensively before they're approved, but those clinical trials involve thousands or tens of thousands of people. Once a vaccine goes into widespread use, millions of people receive it. Rare side effects that might occur in one out of every hundred thousand recipients wouldn't necessarily show up in the trials. VAERS exists to catch those signals.

When the Tripwire Works

In 1999, VAERS did exactly what it was supposed to do.

A new rotavirus vaccine called RotaShield had been approved to prevent a stomach virus that causes severe diarrhea in infants. Shortly after the vaccine's rollout, VAERS started receiving reports of a condition called intussusception—a painful and potentially dangerous situation where part of the intestine folds into itself like a telescope.

The reports triggered an investigation. Researchers examined the data more closely and confirmed that yes, this particular vaccine did increase the risk of bowel obstruction. The vaccine was pulled from the market within a year of its introduction. The system worked. A dangerous pattern was detected, studied, confirmed, and acted upon.

This is the idealized version of how VAERS functions: doctors and nurses notice unusual patterns in their patients, report them to a central database, and public health officials investigate whether those patterns represent genuine safety signals or mere coincidences.

The Problem With an Open Door

But VAERS has a fundamental design choice that creates problems: it doesn't verify reports.

When Jim Laidler claimed to have turned into a green rage monster, no one checked his medical records. No one examined him. No one confirmed that the event he described actually happened. The system is built on trust—the assumption that people submitting reports are doing so in good faith and with accurate information.

This open design was intentional. The architects of VAERS wanted to cast a wide net. They worried that if they made reporting too difficult or burdensome, doctors might not bother, and genuine safety signals might be missed. Better to have too much data than too little, the thinking went. You can always analyze raw data to separate signal from noise.

The problem is that raw data, stripped of context and analysis, tells a story that isn't necessarily true.

Consider what happens when millions of people receive vaccines. Some of those people will get sick afterward—not because of the vaccine, but because people get sick all the time. Some will develop heart disease. Some will have strokes. Some will be diagnosed with cancer. Some, tragically, will die. These things happen in any large population over any period of time. If you vaccinate everyone in a city on Monday, some of them will experience health problems on Tuesday, Wednesday, and the weeks that follow, simply because that's what happens in human populations.

If all those events get reported to VAERS, the database will show vaccines followed by heart attacks, strokes, cancer diagnoses, and deaths. But that doesn't mean the vaccines caused any of those outcomes. It means that vaccination happened to occur before events that would have happened anyway.

Lawyers, Litigation, and Corrupted Data

In the early 2000s, something strange started happening in the VAERS database. Reports mentioning autism began to spike dramatically. Reports involving thimerosal—a mercury-containing preservative that had been used in some vaccines—surged as well.

When researchers investigated, they discovered the source: personal injury lawyers.

A wave of lawsuits had been filed claiming that vaccines, and thimerosal in particular, caused autism in children. The lawyers filing these suits needed evidence to support their claims, and VAERS offered an irresistible opportunity. Anyone could file a report. The reports would become part of an official government database. That database could then be cited in court as evidence of a link between vaccines and autism.

A 2006 study published in the medical journal Pediatrics found that most VAERS reports related to thimerosal and autism during that period were filed in connection with litigation. The data wasn't coming from doctors or nurses or parents who had observed their children. It was coming from lawyers building cases.

Paul Offit, a prominent vaccine researcher and chief of infectious disease at Children's Hospital of Philadelphia, put it bluntly. Public health officials, he wrote, "were disappointed to learn that reports of autism to VAERS weren't coming from parents, doctors, nurses, or nurse practitioners; they were coming from personal-injury lawyers." For those lawyers, VAERS reports "hadn't been a self-fulfilling prophecy; they'd been a self-generated prophecy."

The COVID Era Explosion

The problems with VAERS interpretation exploded during the COVID-19 pandemic.

When COVID-19 vaccines rolled out in late 2020 and 2021, they were administered to unprecedented numbers of people in a very short time. This meant that by sheer statistical probability, many events would occur after vaccination simply because so many people were being vaccinated. Some recipients would have heart attacks within days of their shots. Some would have strokes. Some would die from causes that had nothing to do with the vaccines they'd received.

All of these events could be—and were—reported to VAERS.

Anti-vaccine activists seized on this data. Websites like OpenVAERS published running tallies of adverse events and deaths "linked" to COVID-19 vaccines, drawing their numbers directly from the VAERS database. The National Vaccine Information Center, an organization that opposes vaccine mandates and has been accused of spreading misinformation, published similar data through its Medalerts website.

These tallies looked terrifying. Thousands of deaths! Hundreds of thousands of adverse events! The numbers were real—they really were in the VAERS database—but the implication that vaccines had caused all these outcomes was not supported by the data.

The CDC repeatedly warned that VAERS data alone cannot determine whether a vaccine caused a particular adverse event. The reports are unverified. They may be incomplete. They may be inaccurate. They may describe events that had nothing to do with vaccination. They may, as in Jim Laidler's case, be entirely fictional.

How Vaccine Safety Actually Works

VAERS is just one piece of a larger puzzle. When public health officials evaluate vaccine safety, they don't simply count up VAERS reports and declare a verdict. They use VAERS as a starting point—a way to identify potential signals that warrant further investigation.

The actual investigation happens elsewhere. The Vaccine Safety Datalink, for instance, is a collaboration between the CDC and nine healthcare organizations that covers about three percent of the American population. Unlike VAERS, the Datalink contains verified medical records. Researchers can compare health outcomes in vaccinated people versus unvaccinated people, controlling for age, health status, and other factors. This allows them to determine whether vaccines actually increase the risk of particular outcomes or whether the association is coincidental.

The Clinical Immunization Safety Assessment Network, known as CISA, provides another layer of evaluation. This network of medical experts reviews individual cases of potential vaccine adverse events, providing detailed clinical assessments that go far beyond what VAERS can offer.

When these more rigorous systems investigate claims that emerge from VAERS data, they often find no connection between vaccines and the reported events. The raw numbers that look so alarming in isolation dissolve under scrutiny. The heart attacks and strokes and deaths were happening at rates no different from what you'd expect in an unvaccinated population of similar size and demographics.

The Paradox of Transparency

VAERS represents a genuine dilemma for public health authorities.

On one hand, making the data publicly accessible embodies democratic values. Citizens can see what's being reported. Researchers outside the government can analyze the information. Transparency builds trust—or at least, it should.

On the other hand, public access to raw, unverified data creates opportunities for misinterpretation and manipulation. People who don't understand the system's limitations can draw conclusions the data doesn't support. People who do understand those limitations can exploit public confusion for political or financial gain.

The CDC has tried to address this by including prominent warnings on VAERS data. The database comes with explicit caveats explaining that reports do not prove causation, that anyone can submit a report, and that the data should not be used in isolation to draw conclusions about vaccine safety. But warnings compete poorly with scary numbers. A headline claiming "10,000 Deaths Reported After COVID Vaccination" travels faster than an explanation of why that number doesn't mean what it seems to mean.

Understanding the Risk-Benefit Calculation

All of this matters because vaccines, like all medical interventions, involve tradeoffs.

No vaccine is perfectly safe. Some people will experience genuine adverse reactions—ranging from sore arms and mild fevers to rare but serious complications. The question is never "Is this vaccine completely risk-free?" The question is "Do the benefits of this vaccine outweigh its risks?"

VAERS exists to help answer that question by identifying risks that might not have been apparent in clinical trials. But the system can only do its job when the data is interpreted correctly. When raw VAERS numbers are treated as proof of vaccine danger, the system fails. Worse, it undermines public trust in vaccines that may be genuinely safe and effective.

The rotavirus vaccine story shows what success looks like: a genuine signal was detected, investigated, confirmed, and acted upon. The autism litigation story shows what failure looks like: motivated actors manipulated the system to generate data supporting claims that rigorous research has repeatedly debunked.

Looking Ahead

VAERS will likely remain controversial for as long as vaccines themselves are controversial. Its open design makes it vulnerable to abuse, but changing that design could make it less effective at catching genuine safety signals. There may be no perfect solution—only a constant need for public education about what the system can and cannot tell us.

For anyone encountering VAERS data in the wild, whether in news articles, social media posts, or conversations with friends and family, the most important thing to remember is this: a report in VAERS means someone said something happened after a vaccination. It doesn't mean the vaccination caused it. It doesn't mean the report is accurate. It doesn't mean anything, really, until someone does the hard work of verification and analysis.

Jim Laidler's Hulk transformation was eventually removed from the database, but only because he agreed to its deletion. For all we know, other fictional reports remain, sitting alongside genuine medical observations and lawsuit-driven claims and honest mistakes, all mixed together in a database that offers transparency without truth.

The challenge for public health in the twenty-first century is figuring out how to provide one while working toward the other.