Hyposensitization protocols for pollen allergy involve injections of which substance?

• A. Allergen
• B. Pooled human antisera
• C. Monoclonal antibody directed against human T cells
• D. Monoclonal antibody directed against human B cells

Answer: (A)

Hyposensitization for pollen allergy works by training the immune system through controlled exposure to the actual allergen. In these protocols, injections contain the allergen extract—the pollen proteins themselves—given in gradually increasing amounts. The goal is to shift the immune response away from an IgE-dominated reaction toward tolerance, promoting blocking antibodies and regulatory T-cell activity that lessen reactivity on real allergen encounters. Pooled human antisera would only provide antibodies without teaching the immune system to tolerate the allergen, and monoclonal antibodies aimed at T cells or B cells would modify immune cells directly rather than induce tolerance through exposure to the allergen.