Smallpox is classified as which type of biological agent?

Smallpox is classified as a virus, which is the correct classification. Viruses are microscopic infectious agents that can only replicate inside the living cells of an organism. In the case of smallpox, the virus responsible for the disease is known as Variola virus. This virus is highly infectious and was historically associated with high mortality rates before its eradication through vaccination efforts.

Understanding smallpox as a virus differentiates it from other biological agents such as bacteria, toxins, and protozoans. Bacteria are single-celled organisms that can reproduce on their own, while toxins are harmful substances produced by organisms, and protozoans are single-celled eukaryotic organisms. Identifying smallpox specifically as a virus highlights the unique characteristics that require different types of containment and treatment approaches compared to other biological agents.