Live vaccine

It is the vaccine that contains live microorganisms. As they contain viable microorganisms, they are able to multiply in the pig, so this kind of vaccines have the advantage of stimulating a better and more durable immunity. Nevertheless, they have the disadvantage of going bad more easily (if we keep them under inappropriate conditions, or if remnants of a previous administering remain in the syringe) because the microorganism contained in them die.

Normally, these microorganisms have been attenuated (their infective ability has been reduced) so, although they multiply in the pig, they are not able to cause the disease.