(2) There are three ways to prevent infectious diseases: controlling the source of infection, cutting off the route of transmission, protecting susceptible people, and disinfecting vehicles with dogs, which belong to cutting off the route of transmission;
(3) Vaccines refer to biological products made by inactivating or attenuating pathogens. After being inoculated into human body, it can produce corresponding antibodies, thus improving the resistance to specific infectious diseases, so rabies vaccine belongs to antigen; The immunity obtained by vaccination only works on the corresponding pathogens, and this kind of immunity produced after birth and only works on specific pathogens or foreign bodies is specific immunity.
So the answer is: (1) source of infection (2) cut off the route of transmission (3) antigen specificity.