Final answer:
Vaccinia virus (smallpox) vaccination leads to a long-term memory B cell response, enabling the immune system to rapidly and effectively respond to future exposures to the smallpox virus.
Step-by-step explanation:
The question revolves around the effects of the Vaccinia virus vaccination. When someone receives a vaccination, their immune system is exposed to noninfectious antigens derived from the pathogen, which provokes a mild primary immune response. This does not lead to illness but establishes immune memory. Upon future exposure to the smallpox pathogen, the vaccinated individual experiences a rapid and strong secondary immune response thanks to the long-term memory B cell response. This programmed response is specific and recalls the defense against the pathogen, providing protection.
Therefore, when considering the options given in the question: Vaccinia virus (smallpox) - vaccination = C) Long-term memory B cell response is the most appropriate choice. This response elucidates the fundamental principle of how vaccinations work, including those related to the Vaccinia virus which is used for smallpox vaccination.