Controlled activity mite vaccines for 'barn allergy'.

Three species of mites, Tyrophagus longior, Glyciphagus destructor, and Acarus farris have been isolated from the dust of barns of farms in Orkney. The mites were cultured in amount sufficient for the production of bulk extracts. These were then tested by skin prick in a population of 30 inhabitants of Orkney and potency was assigned in units of biologic activity. The concentrations of the bulk extracts from the different species were adjusted to the same biologic potency and then used to make delayed-release vaccines for injection therapy and aqueous solutions for provocation tests and therapy by the nasal route. The vaccines were then administered by injection to nine subjects at weekly intervals over a period of 2 months. Assessment by questionnaire suggested that there was a significant improvement in the symptoms of eight of the nine subjects. A course of nasal therapy with the aqueous solutions produced no improvement in four out of five subjects.