Thanks Tatyana
The reasoning behind this is that BCG, used for vaccination against TB, primes the cellular immune response so that it can react in a stronger and quicker way not only to TB but to other organisms. This concept was the basis of trials in the 70’s and 80’s to enhance the response of children with leukaemia, so that they can produce cells that can fight residues of the leukaemia after the number of cells were reduced with chemotherapy. The trials showed some promise but this did not translate to a real advantage so that this treatment was abandoned.