In large quantities these subtances would cause the same symptoms the patient is trying to cure. In small, pure, diluted doses, it is not only safe and free from side effects, but it will trigger the body to heal itself. If you've cut open a red onion you'll notice the same symptoms. Homeopathic remedies come in several forms tablets, powders, liquids and ointments. Tablets are the most common and popular.
Tablets are sugar pills with the liquid remedy infused.
A vaccination infects the person with the actual disease. This is why some people may get sick from the vaccination. Homeopathy on the other hand uses a remedy that will produce similar symptoms to the disease. In fact homeopathic remedies can be very useful to offset negative reactions to vaccinations. The important part of selecting the correct remedy is to 'match' the symptom picture of the remedy as closely to your own symptoms.