The orthopoxvirus belongs to the Poxviridae family and is a large, complex double-stranded DNA virus. Its structural features include an outer membrane and a core containing DNA, surrounded by protrusions. Within host cells, the smallpox virus primarily replicates in the cytoplasm, utilizing the cell's machinery for the assembly of viral particles. The virus can manipulate host cell signaling pathways, suppress the host's immune response, and promote the virus's survival and transmission through the expression of specific genes. The orthopoxvirus genome exhibits relatively high stability, but mutations can still occur, affecting its pathogenicity and ability to evade the immune system.