Vaccination and risk groups: how can we really protect the weakest?

Subjects who for their clinical conditions, age, occupational activities or living situations, are at increased risk of acquiring preventable infectious diseases or suffering from their complications, are the object of periodical attempts of identification and offer of vaccination. Several examples can be drawn from the past and from more recent experiences showing that targeted vaccination strategies usually fail to reach most of these subjects. As a matter of fact, obtaining a very high vaccination coverage in risk groups implies a complex integration of responsibilities in identifying, contacting, communicating with and immunizing many different categories of subjects. On the contrary, routine vaccination strategies of one or more cohorts of subjects have always shown the ability (if well implemented) to protect the weakest individuals in the community, due to the establishment of such a community protection as to get a remarkable positive impact even on those that are not immunized. It is ethically unsustainable that universal immunization strategies for diseases with remarkable impact and severity are delayed until an adequate coverage has been reached in subjects at risk, because this would paradoxically mean a serious damage just for those people that are the theoretical object of protection efforts through targeted vaccination strategies.