National Vaccine
Information Center

Your Health. Your Family. Your Choice.
Understanding VAERS Release Dates

The U.S. Government makes periodic releases of VAERS data. Each release is dated according to the latest report placed in the system, so if the release is dated March 2, that means it has all cases that have been entered into VAERS as of March 2.

In the past, the government released data monthly, and the date of the release was the previous month. For example, they would post data on October 17 with data up to September 14, and this release would remain current until the November 17 release. Because of this, there would be times when the data was two months old.

Since the availability of COVID vaccines, the government has begun weekly releases of the data, and each week's data is only one week old. For example, the release made on January 22 includes data up to January 15, and this release remains current until the January 29 release. So now, the data is never more than two weeks old. updates the data as soon as the government releases it, usually within an hour of posting. If you look at the government's search engine, CDC Wonder, you will see the same date as MedAlerts. The two sites are in complete sync, because they are both fed from the government's data releases.

Copyright © 2022 National Vaccine Information Center. All rights reserved.
21525 Ridgetop Circle, Suite 100, Sterling, VA 20166