Is the FDA too reliant on vaccine makers to test vaccine and report problems?
Manufacturers do most vaccine testing because it would be impractical for the FDA to test every batch of every vaccine made. The companies conduct tests for potency and sterility, among other things, and share the results with the FDA. Vaccine makers and regulators test samples of batches, rather than each individual dose. It is impossible to test each dose because individual vials would have to be opened, making all of the vaccine unsterile. A vaccine maker cannot release vaccine without the FDA’s approval, which largely rests on the agency’s review of the manufacturer’s records. The FDA says it does not usually test the final vials of vaccine, but does perform some tests when the product is in bulk form. Government authorities say the contamination of Chiron’s vaccine appeared to occur during the vial-filling stage, one of the trickiest parts of the process because containers have to be open to receive vaccine. Even after the British suspended Chiron’s license, the company maintained
