Koch's postulate's can't work on viruses, that's not how viruses work. How do you propagate an obligate parasite in a pure culture? Mycobacterium leprae (the ca

Koch's postulate's can't work on viruses, that's not how viruses work. How do you propagate an obligate parasite in a pure culture? Mycobacterium leprae (the cause of leprosy) fails Koch's postulates as well, because of the same "pure culture" issue. Plaque assays clearly show viruses exist and they are self controlling due to the dilution of the original sample and their ability to still work when the virus is cloned.