Final answer:
For the treatment of rabies, post-exposure vaccination is used due to the slow progression of the disease, allowing the immune system time to respond and prevent fatal outcomes. Tetanus can also involve vaccination post-exposure, however, it is typically accompanied by the administration of immune globulin.
Step-by-step explanation:
Among the diseases listed, vaccination after the pathogen has been acquired is notable in the treatment of rabies. This is due to rabies virus' slow progression, allowing sufficient time for the immune system to respond to the vaccine and develop antibodies. The rabies vaccine can be administered post-exposure to boost immunity without adding more of the disease-causing virus, effectively preventing the virus from reaching the nervous system and causing fatal neurological consequences.
Vaccination might also be considered in the case of tetanus, although the primary approach after exposure is to provide tetanus immune globulin for immediate passive immunity, followed by vaccination for long-lasting protection. For other diseases such as necrotizing fasciitis, meningococcal meningitis, and plague, treatment does not typically include post-exposure vaccination, as these diseases progress at a pace that doesn't allow such an approach to be effective.