Respiratory Defense CompleteCompare to Viracid by OrthoMolecular Respiratory Defense Complete includes key nutrients, a synergistic blend of the botanical extracts, and with zinc to keep the immune system functioning at an optimal level. The bodys immune system is a complex and dynamic defense system that comes to the rescue at the first sign of exposure to an outside invader. The dynamic nature of the immune system means that all factors that affect health need to be addressed