Allergyshotsaregivenoveraperiodoftime,usually3to5years orlonger.Themedicalnamefortheseshotsisallergen immunotherapy. Thepurposeofallergenimmunotherapyistoprovideprotection againstyourallergysymptoms.Theshotscontainspecificallergens. Allergensaresubstancesinwhichyouareallergic.Typesofallergens ...