1. An immunoconjugate comprising: (a) at least a first single chain effector fragment； and (b) the first and second antigen binding fragments, independently selected from the group consisting of Fv and Fab, in which the first effector fragment is connected by an amino or carboxy terminal peptide bond to the first antigen binding fragment； and wherein the second antigen binding fragment is linked by an amino or carboxy-terminal peptide bond to either I) the first effector fragment or II) the first antigen binding fragment. 2. The immunoconjugate according to claim 1, wherein the immunoconjugate consists essentially of the first effector fragment and the first and second antigen binding fragments that are linked using one or more linker sequences. The immunoconjugate according to claim 1 or 2, wherein the first and second antigen binding fragments are a Fab molecule. The immunoconjugate according to claim 3, wherein the first Fab molecule is linked via the carboxy-terminal amino acid of its heavy or light chain to the amino-terminal amino acid of the heavy or light chain of the second Fab molecule. The immunoconjugate according to claim 4, wherein the second Fab molecule is linked using the carboxy-terminal amino acid of its heavy or light chain to the amino-terminal amino acid of the effector fragment. The immunoconjugate according to claim 4, wherein the effector fragment is linked via its carboxy-terminal amino acid to the amino-terminal amino acid of the first Fab.7 molecule. The immunoconjugate according to claim 3, wherein the first Fab molecule is linked via the carboxy terminus of its heavy or light chain to the amino terminal amino acid of the effector fragment. The immunoconjugate according to claim 7, in which1. Иммуноконъюгат, содержащий:(а) по меньшей мере первый одноцепочечный эффекторный фрагмент； и(б) первый и второй антигенсвязывающие фрагменты, независимо друг от друга выбранные из группы, включающей Fv и Fab,в котором первый эффекторный фрагмент сое
