Recombinant Anti-CCR3 x Anti-CD300 Bispecific Antibody (Tandem scFv-Fc) is designed to be expressed as a homodimer, which has 2+2 antigen-binding valency. This format consists of one Fc region and two tandem scFv fragments, in which the anti-CCR3/CD300 tandem scFv is fused to the Fc domain. The engineered fragment format is used to extend the half-life. This BsAb canreduce eosinophil signaling, inhibit bronchoalveolar lavage fluid inflammation, eosinophil, mast cell mediator release and reverse lung inflammation. It is designed for the research of Asthma therapy.