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.
First, there's the allergy testing -- multiple scratches into the skin with different allergy triggers to identify what the person is allergic to. Then there's the time involved -- weekly injections for three to five months to gradually build resistance followed by several years of monthly maintenance shots. And there's the pain with each allergy shot. There's also the time it takes for the allergy shots to show noticeable results; usually, several months after those weekly building doses are completed. Relief of symptoms can be seen after a few days of antihistamine pills.