Evaluation of Kappaphycus striatus Lectin on SARS-CoV-2 Spike Protein-Specific IgG Responses

The COVID-19 pandemic highlighted the urgent need for novel therapeutics that would balance vaccines and antivirals. Lectins, which are carbohydrate-binding proteins, can interfere with viral glycoproteins and modulate host immune responses. Seaweed lectins are of particular interest due to their specificity for complex glycans present on viral spikes, including SARS-CoV-2. Kappaphycus striatus , widely cultivated in Southeast Asia, is known for its carrageenan but also contains lectins with promising bioactivities. Little is known about the in vivo immunological role of K. striatus lectins. This study evaluates whether lectin from K. striatus affects IgG responses to the SARS-CoV-2 spike protein in mice.