What are the options for injection treatments for seasonal allergies?

Injection Treatments for Seasonal Allergies

Allergen immunotherapy (AIT) through subcutaneous injections is the most effective injection treatment for seasonal allergies, requiring 3-5 years of administration to achieve long-term disease modification and symptom relief. 1

Types of Injection Treatments

Subcutaneous Immunotherapy (SCIT)

• First-line injection therapy for moderate to severe seasonal allergies that don't respond adequately to pharmacotherapy
• Administered as regular injections containing gradually increasing amounts of specific allergens
• Only disease-modifying treatment option that can provide long-term relief after discontinuation 1, 2
• Requires 3-5 years of treatment for optimal long-term efficacy 1, 2
• Provides persistent clinical benefit for at least 3 years after discontinuation when administered properly 1, 3

Ultra-Short-Course Vaccines

• Newer option requiring fewer injections (e.g., Pollinex Quattro)
• Contains modified allergens with adjuvants like monophosphoryl lipid A
• Requires only four preseasonal injections
• Significantly reduces symptom/medication scores compared to placebo 4
• Generally well-tolerated with mainly local injection site reactions

Administration Protocols

Continuous vs. Seasonal Regimens

• Continuous regimen: Administered year-round

  • More effective in the first year of treatment (44% improvement vs. 20% for coseasonal)
  • Better early immunologic response with higher specific IgG4 levels in first year 5

• Coseasonal regimen: Administered only during or before pollen seasons

  • Nearly equivalent efficacy to continuous regimen by the third year
  • May be more convenient for some patients 5

Efficacy and Duration

• Clinical benefits typically begin after 2-4 months of treatment 2
• Maximal clinical effect achieved within 1-2 years 2
• Minimum 3 years of treatment required for long-term clinical efficacy and immunologic tolerance 1, 2
• If no improvement after 2 years of proper administration, consider discontinuing treatment 2

Safety Considerations

• Must be administered in a healthcare setting with professionals capable of recognizing and treating anaphylaxis
• Mandatory 20-30 minute observation period after injection 6
• Contraindicated in patients taking beta-adrenergic blocking agents 6
• Not effective for treating atopic dermatitis, urticaria, or headaches
• Potentially dangerous if used for food or antibiotic allergies 6

Immunologic Effects

• Increases production of inhibitory cytokines (IL-10)
• Induces allergen-specific IgG4 antibodies that inhibit IgE-facilitated binding
• Reduces allergen-specific IgE responses over time
• Creates immunologic tolerance that persists after treatment discontinuation 2, 3

Treatment Algorithm

1. First step: Try standard pharmacotherapy (intranasal corticosteroids, antihistamines)
2. If inadequate response: Consider SCIT for patients with moderate-to-severe symptoms
3. Administration protocol: Choose continuous regimen for faster first-year results
4. Duration: Continue for at least 3 years, evaluate efficacy at 2-year mark
5. After completion: Monitor for symptom recurrence, which may indicate need for additional treatment

SCIT remains the only injection treatment that can modify the disease course of seasonal allergies, providing benefits that extend years beyond the treatment period when administered properly for an adequate duration.