Fact: No cause-and-effect relationship has been established for adverse events in VAERS reports.

Antivax Myth: VAERS proves thousands of serious vaccine injuriesWhy the Myth Exists

The Vaccine Adverse Event Reporting System (VAERS) is a data collection system. The U.S. Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) in 1990 in response to legislation called “National Childhood Vaccine Injury Act”.

There are about 30,000 new reports added to VAERS each year. That sounds like a whole lot of vaccine injuries happening.

Variations on this Myth

  • “Severe vaccine injuries are significantly under-reported in VAERS.”
  • “My doctor won’t let me file a VAERS report.”

Examples Found Online

The Real Deal: What the Evidence Shows

When evaluating data from VAERS, it is important to note that for any reported event, no cause-and-effect relationship has been established.

– VAERS Data page


The National Childhood Vaccine Injury Act (NCVIA) of 1986 requires health care providers to do certain things. They must provide vaccine recipients (or their guardians) a vaccine information sheet with each dose of vaccine. They must also record certain adverse events that patients report. They do this through VAERS.

Vaccines go through rigorous and lengthy clinical trials before approval. They must prove to be safe and effective through three phases in which the number of people studied increases. Safety trials continue after vaccine approval, licensing, and manufacture. Any adverse events experienced during trials, whether or not they are caused by the vaccine, are listed on the package insert.

VAERS provides public health officials with data for early detection of new or increasing adverse effects of vaccines. The data can also help them identify common risk factors or contraindications, and to continue to assess overall vaccine safety.

While is it primarily the responsibility of health providers, anyone can file a VAERS report via mail, fax, or online. Parents simply go to the VAERS website and follow the instructions.

Why are there so many VAERS reports filed every year?

Children in the U.S. under the age of 1 receive over 10 million vaccines each year . This is an age range in which certain medical events are most frequent whether or not an infant is vaccinated: seizures, high fever, and sudden infant death syndrome (SIDS).

In older childhood, there are additional vaccines given. This coincidentally may be a period of several illnesses or injuries. At any given point in early childhood, it is not uncommon for a vaccine and a medical event to happen close in time.

When a medical event occurs, sometimes a parent thinks back to an earlier event such as a vaccination. It is easy to mentally connect the two. So they make a report to VAERS. The submitted reports are all publicly available.


VAERS reports are not screened for causality. As the VAERS Data page states, “no cause-and-effect relationship has been established”.

Laughlin et al completed a study in which they selected 100 VAERS reports at random. They carefully reviewed each one, along with associated medical records. They concluded:

“causality was thought to be probable or definite in less than one quarter of reports, and these were dominated by local reactions, allergic reactions, or symptoms known to be associated with the vaccine administered.”

In other words, over 75% of the VAERS-reported events were probably not caused by vaccines. Those events that vaccines caused were mainly local reactions, due to allergies, or already identified during trials as possible symptoms.

The VAERS website announces that vaccine effects are probably under-reported. But it explains that most adverse events are mild, temporary reactions such as soreness and low-grade fevers. Generally, parents understand these are normal signs of a successful immune response. So they see no need to report them.

When a certain event keeps recurring, it may prompt further controlled study. The data in VAERS is insufficient to confirm a cause-and-effect hypothesis nor determine incidence. The data is simply not complete enough.

Many VAERS reports include completely unrelated events following vaccination. Examples are deaths from drowning, auto accidents, and accidental suffocation due to co-sleeping, or other inadvisable sleeping conditions. One cannot truthfully roll these events into a big collection of “vaccine-caused deaths”.

References and Further Reading


Science-Based Memes and Screenshots