Which of the following are considered viral vaccines? (Select all that apply)

A. Hodgkin disease (also known as Hodgkin lymphoma) is a type of cancer that originates in the lymph nodes. It is characterized by the presence of Reed-Sternberg cells, a specific type of abnormal cell found in the lymphatic tissue.
B. Benign tumors of the spleen are not associated with Hodgkin disease.
C. A malignant tumor of the spleen refers to cancers like splenic lymphoma or metastasis from other organs, but this is not Hodgkin disease.
D. A benign tumor of the lymph nodes is not the correct description for Hodgkin disease, as it is a malignant (cancerous) condition.

A. Autoimmunity is a malfunction of the immune system where the body attacks its own tissues — it is not a type of protective immunity acquired through infection or exposure.
B. Species immunity refers to natural resistance to certain diseases that affect other species (e.g., humans not being susceptible to some animal viruses), not immunity acquired through infection.
C. Passive immunity involves receiving antibodies from another source (like from mother to baby or via antibody-containing injections) and does not require the immune system to produce its own response.
D. Active immunity is the correct answer. It develops when the body is exposed to a pathogen or its toxins and responds by producing its own antibodies and memory cells, providing long-term protection.