Delayed hypersensitivity in mice; its detection by skin tests and its passive transfer

Mice vaccinated intraperitoneally with a water-in-oil emulsion containing ovalbumin and avirulent tubercle bacilli developed strong immediate and delayed hypersensitivities, demonstrable by intracutaneous injection, to the ovalbumin. The two types of hypersensitivity could be differentiated by gross characteristics as well as by passive-transfer experiments with cells and serum from actively sensitized donors.