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.
People with severe symptoms can get a series of allergy shots that prevent or lessen the allergic reaction by training the immune system to accept the allergen. Oddly enough, many people develop allergies after repeated exposures to an allergen.