Table 2. Summary Synopsis of Cochrane meta-analyses for SLIT.

^* Allergens used in the trials evaluated: House Dust Mite allergy (6), Grass Pollen (5), Parietaria (5), Olive (2), Ragweed (1), Cat (1), Tree (1) and Cupressus (1). ** Allergens used in the trials evaluated:: grass pollen (23), Parietaria (5), ragweed (2), trees (9: 2 olive, 3 cypress, 2birch pollen, 2 mixed trees), house dust mite (8) and cat (1). One of the trials investigated the efficacy of grass and birch pollen immunotherapy.