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What is SMART caries vaccine is a form of: and explain in detail?
SMART in Smart caries vaccine denotes "S. Mutans and Replacement Therapy". 
Jeﬀrey Hillman from the University of Florida developed a genetically modiﬁed strain of Streptococcus mutans called BCS5- L1 that is incapable of producing lactic acid - the acid that dissolves tooth enamel - and aggressively replaces native ﬂora. In laboratory tests, rats that were given BCS311 were conferred with a lifetime of protection against S. mutans. BCS3-L1 colonizes the mouth and produces a small amount of a lantibiotic, called MU1140, which allows it to outcompete S. mutans. Hillman suggested that treatment with BCSL1 in humans could also provide a lifetime of protection, or, at worst, require occasional reapplications.