It is a common anti-vax myth that vaccines are only tested for four or five days before they are approved.
Most immunization side effects are mild and only last a few days.
Did the CDC say that it is impractical to find out of vaccines are causing an epidemic of brain injury and other long-term health problems? I’m guessing they didn’t… Are Vaccines Causing Long-Term Health Problems? Why does anyone think that they did? Oh, anti-vaccine folks are sharing a cherry-picked quote from the CDC to scare …
A list of long-term studies on vaccine safety to help you see that vaccines are safe.