Tree MATAMPL has been developed to provide pre-seasonal specific immunotherapy for patients with hypersensitivity to Tree (birch, alder, hazel) pollen (hay fever). This novel formulation is designed to provide a vaccine that will be efficacious with only four escalating dose injections administered before the start of the pollen season. In this Study the Efficacy will be assessed by exposing allergic subjects to birch pollen in an environmental exposure chamber EEC. Patient symptomatic response to birch pollen and patient quality of life in the EEC will be determined.