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  6. Vaccine Adverse Event Reporting System (VAERS) Questions and Answers
  1. Vaccine Adverse Events

Vaccine Adverse Event Reporting System (VAERS) Questions and Answers

Defining VAERS

What is VAERS?

VAERS is a national vaccine safety surveillance program created as an outgrowth of the National Childhood Vaccine Injury Act of 1986 (NCVIA) and is administered by the Food and Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC). VAERS collects and analyzes data from reports of adverse events following vaccination.

Since 1990, VAERS has received over 123,000 reports, most of which describe mild side effects such as fever. Very rarely, people experience serious adverse events following immunization. By monitoring such events, VAERS helps to identify any important new safety concerns that otherwise may not come to light before licensure.

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Questions about Reporting to VAERS

Who can report to VAERS?

Anyone can report to VAERS. VAERS reports are usually submitted by health care providers, vaccine manufacturers, vaccine recipients (or their parents/guardians) and state immunization programs. Patients, parents, and guardians are encouraged to seek the help of a health-care professional in reporting to VAERS.

Why should I report to VAERS?

VAERS is a valuable tool for post-marketing safety surveillance. Each report provides valuable information that is added to the VAERS database. Complete reporting of post-vaccination events supplies public health professionals with the information they need to ensure the safest strategies of vaccine administration.

What events should be reported to VAERS?

VAERS encourages the reporting of any significant adverse event occurring after the administration of any vaccine licensed in the United States. You should report any significant adverse event even if you are unsure whether a vaccine caused the event.

The National Childhood Vaccine Injury Act (NCVIA) requires health care providers to report:

  • Any event listed by the vaccine manufacturer as a contraindication to subsequent doses of the vaccine.
  • Any event listed in the Reportable Events Table that occurs within the specified time period after vaccination.

The Reportable Events Table specifically outlines the reportable post-vaccination events and the time frames in which they must occur in order to qualify as being reportable. To obtain a copy of the Reportable Events Table, call 1-800-822-7967 or go to http://www.vaers.hhs.gov/reportable.htm.

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Possible Outcomes of Reporting to VAERS

How are VAERS reports analyzed?

Both the CDC and the FDA review data reported to VAERS. The FDA reviews reports to assess whether a reported event is adequately reflected in product labeling, and closely monitors reporting trends for individual vaccine lots. Approximately 85% of the reports describe mild events such as fever, local reactions, episodes of crying or mild irritability, and other less serious experiences. The remaining 15% of the reports reflect serious adverse events involving life-threatening conditions, hospitalization, permanent disability, or death, which may or may not have been truly caused by an immunization.

Can information reported to VAERS cause a recall of a vaccine?

The FDA has the authority to recall a vaccine from use in the United States if they feel it represents a risk to the American public. VAERS reports may signal that there is the potential for a safety risk, which would prompt a wider evaluation of the safety of the vaccine lot. If the evaluation confirms a risk, the batch can be recalled.

Are all events reported to VAERS caused by vaccinations?

No. Because VAERS accepts all reports of adverse events following vaccination, not all events reported to VAERS are caused by vaccines. Some events may occur coincidentally after the administration of a vaccine while others may in fact be caused by a vaccine. Studies help determine if there is more than a temporal (time) association between immunization and adverse events. An occurrence of an adverse event following the administration of a vaccine is not conclusive evidence that the event was caused by the vaccine. Various factors (e.g., medical history, other medications given near the time of the vaccination) must be examined to determine if they could have caused the adverse event. Many adverse events reported to VAERS may not be caused by vaccines.

What if I can't tell if a reaction was caused by a vaccine or another medication?

We encourage you to report any reaction following vaccination to VAERS, even if you cannot tell if the vaccine or another product caused it. Reports sent to the VAERS program that also make reference to non-vaccine pharmaceutical products are shared with MedWatch, the FDA's drug safety surveillance system.

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For More Information about VAERS

Where Can I find out more information about electronic reporting to VAERS? 

Information concerning regulatory submissions in electronic format for biologics products can be found at: https://www.fda.gov/vaccines-blood-biologics/development-approval-process-cber/regulatory-submissions-electronic-format-biologic-products.

How do I find out if a vaccine adverse event has been reported to VAERS?

The Freedom of Information Office can be contacted to obtain specific data from VAERS. The requester will be billed for the cost of retrieving and copying the data. You can request information about adverse events reported to VAERS by faxing requests to (301) 443-1726, or by sending requests to:

Food and Drug Administration
Freedom of Information Staff (HFI-35)
5600 Fishers Lane
Rockville, MD 20857
(301) 827-6500

Is VAERS involved in the Vaccine Injury Compensation Program?

No. The National Childhood Vaccine Injury Act created the Vaccine Injury Compensation Program (VICP) to compensate individuals whose injuries may have been caused by vaccines recommended by the CDC for routine use. VICP is separate from the VAERS program. Reporting an event to VAERS does not file a claim for compensation to the VICP. A petition must be filed with VICP to start a claim for compensation. For more information call (800) 338-2382, or go to http://www.hrsa.gov/vaccinecompensation/index.html.

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