The present invention relates to allergy vaccines and methods of treating and / or preventing asthma, and allergic conditions. The invention is based on the discovery that inhibiting the ligand / receptor interactions involving, e.g., IgE, IL-3, IL-4, IL-5, IL-6, IL-10, IL-13, interferon-alpha, histamine, leukotriene, and their respective receptors, inhibits production of IgE thereby treating or preventing such diseases or conditions. Competitive inhibition of such receptor / ligand interactions is accomplished by immunizing a human or veterinary patient with the interleukin, interferon-alpha, histamine, leukotriene, their receptors, in any combination. Also, the invention relates to inhibiting receptor / ligand interactions involved in IgE production by competitively inhibiting such interactions by administering antibodies to the ligands, receptors, or both, as well as by administering analogs of the receptors (e.g., soluble receptors not associated with a cell).