Nobel Prize lau­re­ate Elie Metch­nikoff, the first mod­ern sci­en­tist to claim that human beings have innate cura­tive pow­ers, was once named one of the ten great­est men in the world. Yet today this Russ­ian-Jew­ish zool­o­gist is lit­tle known, despite his last­ing influ­ence in many areas of sci­ence. He spurred the study of aging with his con­tro­ver­sial the­o­ry that peo­ple could live 150 years. He intro­duced the West­ern world to yogurt, mak­ing a rev­o­lu­tion­ary impact on the diets of future gen­er­a­tions world­wide. And his dar­ing the­o­ry of immu­ni­ty earned him the 1908 Nobel Prize in Phys­i­ol­o­gy and Med­i­cine, shared with his arch-rival, also a Jew. Metch­nikoff attrib­uted his own love of sci­ence to his Jew­ish roots. ​“Immu­ni­ty” revives the fas­ci­nat­ing sto­ry of this tow­er­ing fig­ure of the ear­ly 20th century.