If a plate with oceanic lithosphere meets another plate, the dense oceanic lithosphere dives beneath the other plate and sinks into the mantle: this process is called subduction. The sinking oceanic lithosphere drags the rest of the tectonic plate: this is the main cause of plate motion.
You may notice a decrease in symptoms during the build-up phase, but it may take as long as 12 months on the maintenance dose to notice an improvement. If allergy shots are successful, maintenance treatment is generally continued for three to five years.
Months: The reason that allergy shot regimens take years to complete is because they have to go up on the dosage of allergen very slowly. The results are usually very good but it takes months for you to notice a significant difference. Continue taking your oral allergy medications as long as the allergist recommends it.