Extracts of seaweed or marine algae prepared for medical use; extracts of seaweed or marine algae prepared for therapeutic use; extracts of seaweed or marine algae prepared for dietary or nutritional supplement use; extracts of seaweed or marine algae having an anti-viral effect; therapeutic agents (medical); therapeutic biological products (medical); therapeutic biological products containing extracts of seaweed or marine algae (medical); anti-viral agents