Paracelsus (1493–1541) lived well before the age of vaccines.
He is though often thought of as the father of toxicology, famously saying that:
Solely the dose determines that a thing is not a poison
This principle continues to be used today, helping to point out that small amounts of chemicals in vaccines are not toxic or poisonous.
For more information:
- Simple math – the dose makes the poison
- The dose makes the poison
- Vaccines and toxins, more misunderstanding
- The “toxin gambit” resurrected