02487nas a2200217   4500000000100000008004100001100001300042700001200055700001500067700001300082700001300095700001700108700001700125700001200142700001300154700001400167700001100181245012800192856008700320520186200407       2018                            d1 aDuthie M1 aPena MT1 aEbenezer G1 aGillis T1 aSharma R1 aCunningham K1 aPolydefkis M1 aMaeda Y1 aMakino M1 aTruman RW1 aReed S00aLepVax, a defined subunit vaccine that provides effective pre-exposure and post-exposure prophylaxis of M. leprae infection  uhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC5871809/pdf/41541_2018_Article_50.pdf3 a<p>Sustained elimination of leprosy as a global health concern likely requires a vaccine. The current standard, BCG, confers only partial protection and precipitates paucibacillary (PB) disease in some instances. When injected into mice with the T helper 1 (Th1)-biasing adjuvant formulation Glucopyranosyl Lipid Adjuvant in stable emulsion (GLA-SE), a cocktail of three prioritized antigens (ML2055, ML2380 and ML2028) reduced <em>M. leprae</em> infection levels. Recognition and protective efficacy of a single chimeric fusion protein incorporating these antigens, LEP-F1, was confirmed in similar experiments. The impact of post-exposure immunization was then assessed in nine-banded armadillos that demonstrate a functional recapitulation of leprosy. Armadillos were infected with <em>M. leprae</em> 1 month before the initiation of post-exposure prophylaxis. While BCG precipitated motor nerve conduction abnormalities more rapidly and severely than observed for control infected armadillos, motor nerve injury in armadillos treated three times, at monthly intervals with LepVax was appreciably delayed. Biopsy of cutaneous nerves indicated that epidermal nerve fiber density was not significantly altered in <em>M. leprae</em>-infected animals although Remak Schwann cells of the cutaneous nerves in the distal leg were denser in the infected armadillos. Importantly, LepVax immunization did not exacerbate cutaneous nerve involvement due to <em>M. leprae</em> infection, indicating its safe use. There was no intraneural inflammation but a reduction of intra axonal edema suggested that LepVax treatment might restore some early sensory axonal function. These data indicate that post-exposure prophylaxis with LepVax not only appears safe but, unlike BCG, alleviates and delays the neurologic disruptions caused by <em>M. leprae</em> infection.</p>