EC Microbiology

The principle on which vaccines are based is to inoculate a healthy subject with attenuated quantities (or parts of it) of the pathogenic agent so as to provoke an immune reaction capable of protecting it. In addition to this benefit, there is another equally important one: the vaccination of a single individual reduces the number of subjects who can transmit the infection. Therefore, we have what has been defined as “herd immunity” which ends up providing protection even to individuals who have not been vaccinated.