Virus - An infectious agent that is only capable of replicating itself inside the living cells of other organisms.⏎
Transition Zone - The area, sometimes referred to as an ecotone, encompassing the edges of two distinct ecosystems, such as the area where a forest intersects with grassland.⏎
Toxin - A poisonous substance, often a protein, produced by the metabolic processes of living cells or organisms that can cause disease if introduced into the body.⏎
Vaccine - A biological preparation that improves the immune system’s ability to recognize and destroy harmful infectious agents.⏎
World Health Organization (WHO) - The directing and coordinating authority for health within the United Nations system, responsible for providing leadership on global health matters, shaping the health research agenda, setting norms and standards, articulating evidence-based policy options, providing technical support to countries and monitoring and assessing health trends.⏎