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.
Some patients will notice an early improvement of symptoms within several weeks during the build up phase, but it may take as long as 6 to 12 months on the maintenance dose to see a significant improvement. The effectiveness of immunotherapy is related to the strength of allergy vaccines and the length of treatment.