Langerhans cells at the sites of vaccinia virus inoculation.

Langerhans cells in the epidermis at the sites of vaccina virus inoculation were studied with the electron microscope. The cells contained unusually increased numbers of the Langerhans cell granules. Such abnormal Langerhans cells have not been described except for in histiocytosis X. Vaccinia virus particles were found in the Langerhans cells, where they were located individually or embedded in the granular matrix or in lysosomes.