"Oral BCG was used in recent clinical studies and it was found that revaccination orally induces circulating cell-mediated immune responses, but does not induce a positive TST in responsive individuals."
Anything that makes you apply your hand to your face.
"Oral BCG was used in recent clinical studies and it was found that revaccination orally induces circulating cell-mediated immune responses, but does not induce a positive TST in responsive individuals."