A division of your immune system called cell mediated immunity is charged with stopping viral infections. The main actors of that are called cytotoxic T cells who, when they encounter a cell that is displaying viral antigens on its surface, binds to the cell and releases toxic substances called perforins and granzymes that destroy and digest the viral infected cell.
Rather than helping one species you can help a entire ecosystem. if you think about it, you would be saving more in a ecosystem then you would in just 1 single species
