Here it is: Proponents claim a vaccine stimulates a person’s immune system to produce antibodies, which are immune-system scouts.
This is supposedly a rehearsal. The immune system gets a chance to respond to a “test run,” so that when the real disease hits, the immune-defense will be ready and will knock out the disease quickly.
Except there are many diagnostic tests for disease that look for antibodies, and if antibodies show up, the doctor tells the patient he has the disease.
It's why I stopped vaxxing my dogs for Lyme - once they get the vax, you never truly know if they have the disease or if you are just seeing the vaccination floating around. Older dog - positive for anaplasma (similar to lyme) and was vaxed as a pup, always has iffy test results for Lyme. Younger guy - never vaxed for Lyme therefore ANY presence would be a true positive result for Lyme disease.