White spot syndrome virus (WSSV) is currently the most serious viral pathogen of shrimp worldwide. It causes up to 100% mortality within 7 to 10 days in shrimp farms, resulting in huge economic losses. Recently, the effectiveness of oral vaccination with WSSV recombinant proteins in giant freshwater prawn (Macrobrachium rosenbergii), whiteleg shrimp (Penaeus vannamei), kuruma shrimp (Marsupenaeus japonicus), and crayfish has been documented. In this study, we investigated the effectiveness of oral delivery of surface-displayed VP28 on Bacillus subtilis spores (VP28-Bacillus subtilis) in Penaeus monodon upon immersion challenge with WSSV. The immune parameters, including haemocyte count, phenoloxidase activity, and superoxide dismutase activity were evaluated for different feeding regimes. Through the value of relative percent survival, the type and feeding regime were determined in order to achieve the highest survival rate of Penaeus monodon after WSSV immersion challenge.