CISA Evaluation

If you are a US healthcare provider with a vaccine safety question about a specific patient residing in the US that is not readily answered by Advisory Committee on Immunization Practices (ACIP) guidelines and you seek expert opinion, you can contact CDC to request a CISA evaluation. This service is provided free of charge.

CDC’s Immunization Safety Office (ISO) reviews requests from US healthcare providers for consultation to address vaccine safety questions regarding patients residing in the US. CDC will determine whether this inquiry should be forward to CISA for an in-depth evaluation.

  • Only selected inquiries will be forwarded for a CISA evaluation.
  • Providers will be notified, usually within 1-2 weeks after submission of a request, if the case will be reviewed by CISA.
  • If the question is not forwarded for a CISA evaluation, then CDC will address the question or send it to another appropriate channel for a response.
  • There is no cost to the provider for a CISA evaluation.

Advice from CDC and CISA is meant to assist in decision-making, rather than provide direct patient management.  Patient management decisions are the responsibility of the treating healthcare provider. CISA might require up to three months to collect and review all pertinent medical records, review the medical literature, review vaccine safety surveillance reports for similar reports of adverse events, and discuss the case on a clinical consultation call with CISA members and the patient’s healthcare provider. If your patient is experiencing a medical emergency, call 911 or your local emergency service provider.

To request a CISA evaluation, please provide your name, health professional training category (e.g., MD, DO, NP, PA, RPh), and your phone number in your email. Please include enough clinical background information in your question to enable CDC to triage your inquiry appropriately. Please do not list patient names or personal identifying health information in your email; CDC or CISA staff will contact you if more information is needed.

If you are not a healthcare provider and you have a vaccine safety question, you can either:

  1. Ask your healthcare provider to send an inquiry to CISAeval.
  2. Call 1-800-CDC –INFO line directly with your question. The 1-800-CDC-INFO line accepts questions on any health issue (including vaccine safety) from both patients and healthcare providers. Healthcare providers who would like a quick response to their vaccine safety question can also contact this line. See this link for more information:

What happens in a CISA evaluation?

In a CISA evaluation, vaccine safety experts from the CDC’s Immunization Safety Office and the CISA academic medical centers meet via scheduled conferences to review complex vaccine safety cases from US healthcare providers.

During these reviews, an investigator presents the clinical case, which includes the history of present illness (the adverse event following vaccination), and detailed physical examination and diagnostic (laboratory and other) findings. A summary of a literature related to the condition and the Vaccine Adverse Event Reporting System (VAERS) data are also presented. The experts discuss the findings and form a general assessment and plan. When appropriate, these conclusions are shared with the healthcare provider. The healthcare provider may also attend the case presentation and participate in the discussion. Usually CISA investigators and CDC have no direct contact with the patient.

 Top of Page


If you are a US healthcare provider with a vaccine safety question about a specific patient residing in the US that is not readily answered by ACIP guidelines, and need expert opinion, you can contact CDC at to request a CISA evaluation.

If you or your patient has had a clinically significant adverse event following a vaccine, please report it to VAERSExternal.

If you have a question on any health issue, including vaccine safety, you may also call 1-800-CDC-INFO.

If you feel you need information on how to file a claim with the National Vaccine Injury Compensation ProgramExternal , please visit