Disclosed herein is a novel monoclonal antibody exhibiting binding affinity to Siglec-3 receptor. According to the embodiment, the monoclonal antibody is capable of reversing HBV-induced immunosuppression. Accordingly, also disclosed herein are the uses thereof in the treatment and/or prophylaxis of hepatitis B virus (HBV) infection.本揭示內容是關於對Siglec-3受器具有結合親和力的新穎單株抗體。依據實施方式,該單株抗體可回復由HBV所媒介的免疫抑制反應。因此,本揭示內容亦提供該單株抗體於治療及/或預防B型肝炎病毒(HBV)感染的用途。