The Claim:
On Del Bigtree’s internet show, lawyer Aaron Siri claims that the whole childhood vaccine schedule is unsafe because, according to him, none of the vaccines were ever tested the right way with real placebo groups.
The Facts:
Siri says that most childhood vaccines are tested against other vaccines instead of a simple salt-water placebo. But in real life, many vaccines have been tested using saline placebos to check safety and how well they work, including:
- Rubella vaccine
- Pneumococcal vaccine
- Hib vaccines
- HPV vaccine
- The Salk Polio vaccine
- Measles vaccine
- Tdap vaccine
- COVID vaccine
Sometimes a new vaccine is compared to an older vaccine, or the placebo may have tiny amounts of things like adjuvants or stabilizers that scientists already know are safe.
The World Health Organization has rules for when using a placebo is fair and safe. It is okay to use a placebo when no good vaccine exists yet and the study could help protect people. But if a country already has a safe, effective vaccine, it is not ethical to give people a placebo instead, because that would leave them unprotected and at risk.
Disclaimer: Science is always evolving and our understanding of these topics may have evolved too since this was originally posted. Be sure to check out our most recent posts and browse the latest Just the Facts Topics for the latest.

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