National Vaccine
Information Center

Your Health. Your Family. Your Choice.
Foreign VAERS Cases

Many people ask why gives different results than the government site, CDC Wonder. This is because of foreign cases.

VAERS includes many reports from outside of the United States. Between 10 and 15 percent of the cases are listed as "foreign" instead of showing a state name.

CDC Wonder, by default, ignores foreign cases when doing a search, whereas MedAlerts defaults to searching the entire VAERS database. This means that a search for any given vaccine will show more cases in MedAlerts. Neither site is lying, they're just interpreting the VAERS data differently.

If you want to align the results, you have two choices:

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