01655nas a2200325   4500000000100000008004100001260001300042653001500055653001000070653001600080653001000096653002100106653002700127653001100154653002300165653001100188653002000199653001200219653001800231653002000249653001700269100001700286700001500303700001300318245008400331300001000415490000700425520088300432022001401315       1981                            d  c1981 Mar10aAdolescent10aAdult10aBCG Vaccine10aChild10aChild, Preschool10aEnvironmental Exposure10aHumans10aImmunity, Cellular10aInfant10aInfant, Newborn10aleprosy10aMycobacterium10aTuberculin Test10aTuberculosis1 aStanford J L1 aShield M J1 aRook G A00aHow environmental mycobacteria may predetermine the protective efficacy of BCG.  a55-620 v623 a<p>A proposal is made that there are 2 mechanisms of cell mediated response to mycobacteria, both of which produce positive tuberculin tests and that one of them is more protective against mycobacterial infection than is the other. These are referred to respectively as the Listeria-type and the Koch-type of responses. Contact with environmental mycobacteria will induce one or other of these types of response and BCG vaccination will enhance it. Thus in those places where the environmental species prime for the Listeria-type of response subsequent BCG vaccination will afford good protection from both tuberculosis and leprosy. Where the Koch-type of response frequently results from environmental contact BCG will be ineffective. Evidence if presented that a large contact with Mycobacterium scrofulaceum is prejudicial to at least one marker of BCG efficacy in Burma.</p>  a0041-3879