VAERS Home

The Vaccine Adverse Event Reporting System (VAERS) is a national early warning system to detect possible safety problems in U.S. licensed vaccines. VAERS is co-managed by the Centers for Disease Control and Prevention (CDC) and the U.S. Food and Drug Administration (FDA). VAERS accepts and analyzes reports of adverse events (possible side effects) following vaccination.

VAERS is not designed to detect if a vaccine caused an adverse event, but it can identify unusual or unexpected patterns of reporting that might indicate possible safety problems requiring a closer look.

VAERS is co-administered by the Centers for Disease Control and Prevention (CDC) and the U.S. Food and Drug Administration (FDA)- agencies of the U.S. Department of Health and Human Services (HHS).

VAERS accepts reports from anyone. Patients, parents, caregivers and healthcare providers (HCP) are encouraged to report adverse events after vaccination to VAERS even if it is not clear that the vaccine caused the adverse event. In addition, HCP are required to report certain adverse events after vaccination.

Healthcare providers are required by law to report to VAERS:

• Any adverse event listed in the VAERS Table of Reportable Events Following Vaccination that occurs within the specified time period after vaccination
• An adverse event listed by the vaccine manufacturer as a contraindication to further doses of the vaccine

Healthcare providers are strongly encouraged to report:

• Any adverse event that occurs after the administration of a vaccine licensed in the United States, whether or not it is clear that a vaccine caused the adverse event
• Vaccine administration errors

Vaccine manufacturers are required to report to VAERS all adverse events that come to their attention.

Serious adverse events are defined as:

• Death
• A life-threatening adverse event
• Inpatient hospitalization or prolongation of existing hospitalization
• A persistent or significant incapacity or substantial disruption of the ability to conduct normal life functions
• A congenital anomaly/birth defect
• An important medical event that based on appropriate medical judgement may jeopardize the individual and may require medical or surgical intervention to prevent one of the outcomes listed above

Vaccination providers must report all serious* adverse events following administration of JYNNEOS or ACAM2000 vaccine and vaccine administration errors to the Vaccine Adverse Event Reporting System (VAERS).

Vaccination providers must report the following listed events following JYNNEOS or ACAM2000 vaccination to VAERS:

• Vaccine administration errors whether or not associated with an adverse event(AE)
• Serious* adverse events (irrespective of attribution to vaccination)
• Cases of cardiac events, including myocarditis and pericarditis
• Cases of thromboembolic events and neurovascular events

*Serious adverse events are defined as:

• Death
• A life-threatening adverse event
• Inpatient hospitalization or prolongation of existing hospitalization
• A persistent or significant incapacity or substantial disruption of the ability to conduct normal life functions
• A congenital anomaly/birth defect
• An important medical event that based on appropriate medical judgement may jeopardize the individual and may require medical or surgical intervention to prevent one of the outcomes listed above

Providers are encouraged to also report to VAERS any additional clinically significant adverse events (AEs) following vaccination, even if they are not sure if vaccination caused the event.

As of August 9, 2022, FDA issued an Emergency Use Authorization (EUA) for JYNNEOS monkeypox vaccine. It authorizes the vaccine to be administered in one of two ways:

1. Intradermally (between the layers of the skin) on the inner aspect of the forearm, and
2. Subcutaneously (under the skin) in the upper arm above the elbow.

These are considered routes of vaccination. When submitting a VAERS report, please ensure that you document the Route in Section 17 of the VAERS form, by choosing “intradermal” or “subcutaneous” from the selection menu.

Each report of an adverse event provides valuable information that is added to the VAERS database. VAERS serves as an early warning system to detect possible safety problems in U.S. licensed vaccines. Accurate, complete, and timely reporting of post-vaccination health issues provides important information for vaccine safety monitoring and research.

Patient identity is kept confidential. VAERS complies with all U.S. Government security standards and protections concerning health information.

Click here to submit a report to VAERS.

We encourage you to report any clinically important medical event or health problem that occurs after vaccination. Report the adverse event even if you are not sure if it was a result of vaccination. Healthcare professionals are required by law to report certain adverse events.

Yes. If you provide your contact information when you submit a VAERS report, you will receive a confirmation number electronically or a VAERS identification number by mail, depending on your method of reporting. This serves as confirmation that your report was received.

If you have your VAERS identification number, you can access a copy of your report at the CDC VAERS WONDER  website. For help getting your report, contact VAERS at (800) 822-7967 or info@vaers.org. If you want information beyond what's available on CDC WONDER, contact FDA and possibly submit a Freedom of Information Act (FOIA) request.

Food and Drug Administration
Division of Freedom of Information
Office of the Executive Secretariat, OC
5630 Fishers Lane, Room 1035
Rockville, MD 20857
Phone: 301-796-3900
Fax: 301-827-9267

You will be contacted by VAERS if follow-up information (i.e., medical records or other medical documentation) is needed. All follow-up information should be faxed to 877-721-0366 or submitted online by auto upload on the VAERS website. Be sure to include your E-number or VAERS identification number with the follow-up. To protect information security and confidentiality, do not mail or e-mail medical records or other medical information.

You may also provide follow-up information in response to a VAERS acknowledgment or follow-up letter you may receive. If you have questions about how the Health Insurance Portability and Accountability Act of 1996 (HIPAA) applies to VAERS, please visit our VAERS Privacy Policies and Disclaimers section.

One of the main limitations of VAERS data is that it cannot determine if the vaccine caused the reported adverse event. This limitation has caused confusion in the publicly available data from VAERS WONDER, specifically regarding the number of reported deaths. There have been instances where people have misinterpreted reports of deaths following vaccination as deaths caused by the vaccines; that is not accurate. VAERS accepts all reports of adverse health events following vaccinations without judging whether the vaccine caused the adverse health event. Some reports to VAERS represent true vaccine reactions and others are coincidental adverse health events and not related to vaccination. Overall, a causal relationship cannot be established using information from VAERS report alone.

Strengths of VAERS:

• VAERS collects national data from all U.S. states and territories
• VAERS accepts reports from anyone
• The VAERS form collects information about the vaccine, the person vaccinated and the adverse event
• Data are publicly available
• VAERS can be used as an early warning system to identify rare adverse events
• VAERS is a tool for identifying potential vaccine safety concerns that need further study using more robust data systems

Limitations of VAERS:

• It is generally not possible to find out from VAERS data if a vaccine caused the adverse event
• Reports submitted to VAERS often lack details and sometimes contains errors
• Serious adverse events are more likely to be reported than non-serious events
• Numbers of reports may increase in response to media attention and increased public awareness
• VAERS data cannot be used to determine rates of adverse events

No. Some adverse events might be caused by vaccination and others might be coincidental and not related to vaccination. Just because an adverse event happened after a person received a vaccine does not mean the vaccine caused the adverse event.

VAERS accepts reports of adverse events following vaccination without judging the cause or seriousness of the event. VAERS is not designed to determine if a vaccine caused an adverse event, but it is good at detecting unusual or unexpected patterns of reporting that might indicate possible safety problems that need a closer look.

VAERS data and individual reports without personally identifying information are available to the public on the VAERS and CDC WONDER websites.

No. Please contact your doctor or healthcare professional to discuss the specifics of your case. Healthcare professionals can request a clinical consultation for particularly complex individual patient cases by contacting the CDC's Clinical Immunization Safety Assessment (CISA) Project. For information on CISA consults, visit https://www.cdc.gov/vaccinesafety/ensuringsafety/monitoring/cisa/index.html.

No. The Vaccine Injury Compensation Program (VICP) is a separate program from VAERS and is administered by the Health Resources and Services Administration (HRSA). Reporting an adverse event to VAERS does not constitute filing a claim with the VICP. For more information about the VICP, call (800) 338-2382 or visit the VICP Web site.