Vaccine Bodies

VACCINE BODIES, in the strict sense, represent special inclusions in the protoplasm of epithelial cells that form after inoculation with pathogenic products of natural smallpox and vaccine, and are strictly specific to the named diseases. They were first described in 1892 by Guarnieri in the epithelium of the rabbit cornea, which is the best object for studying these formations named by Guarnieri Cytorrhyctes vacciniae [see the separate plate (pp. 351-352), Fig. 5]. On sections of the vaccinated cornea, 2-3 days after inoculation, vaccine bodies, or Guarnieri bodies, are easily detected by most nuclear stains. Their size and shape are very diverse: most often they are round or oval formations, surrounded by a light halo and located in a bay-like indentation of the nucleus. Their size usually does not exceed the size of the nucleus. Described, in addition, are bodies without a membrane and halo, structureless, ranging in size from a barely distinguishable point to 3 microns, bodies surrounded by a belt of small grains, then bodies in the form of spheres, half-moons, crescents, spindles, pyramids, etc. According to Guarnieri's opinion, the bodies described by him are the causative agent of the vaccine. However, the majority of researchers are inclined to regard these formations as a product of nuclear degeneration or a product of cellular reaction to the presence of the parasite of vaccine and smallpox. Prowazek discovered so-called "initial bodies" (Initialkörperchen) in vaccine bodies, very small round formations multiplying by division. Subsequently, these bodies become enveloped by reactive products of the cell and by further division give rise to "elementary bodies," gradually filling the entire protoplasm of the cell. Paschen discovered elementary bodies in the transparent lymph of vaccine pustules of a child, and most recently also in the contents of variolous pustules, in vaccine pustules of calves, rabbits, and other animals: these are the smallest, about ¹/₄ μ in diameter, round formations, located singly or in the form of diplococci [Paschen's elementary bodies, see separate plate (pp. 351-352), Fig. 6]. To detect them, a thin smear of the transparent contents of the pustules is dried in the air, immersed for 10 minutes in distilled water, dried, fixed for 5 minutes in methyl alcohol, treated with filtered Löffler's mordant with heating for 2-3 minutes, washed, stained with Ziehl's carbol-fuchsin with heating, washed, dried, and examined with an immersion system. Paschen's data are confirmed by other authors (Prowazek, da Rocha-Lima, and others). Elementary bodies pass through bacterial filters, but are retained by colloidal ones. Attempts to obtain elementary bodies in pure culture on artificial nutrient media have not yielded fully convincing results. The ability to cause the formation of Guarnieri's vaccine bodies is characteristic exclusively of the virus of natural smallpox and vaccine, but not of the virus of chickenpox (varicella). Recently, this fact has been used by Paul for the experimental diagnosis of natural smallpox and its differentiation from certain other pox-like diseases (see Smallpox).