A method for administration of an IgG preparation by an intradermal (ID) route to a subject includes loading with a volume of the IgG preparation an ID delivery device including needles, applying the device to a skin delivery site, using the device to allow dermal penetration of the needles, delivering the volume of the IgG preparation at the skin delivery site, and removing the injection delivery device. The method can be used in the treatment of a disease, such as an immunodeficiency.