A very "leaky gut" will indiscriminately allow the influx of foreign proteins into the body.

So, how do those antibodies arrive?Well, we believe that it's some foreign protein that the body is reacting to. See,that's what antibodies are for.

Vaccine production is in accordance with WHO technical specifications, including detailed screening for adventitious viruses.

Only a high-impact "exogenous" shock like a major war -- something similar to what Krugman called the "coordinated fiscal expansion known as World War II" -- would be enough to break the cycle.

There is a risk that introducing a foreign gene into, for example, a plant may cause it to become allergenic.