For covid-19, a disease that has proved fatal in many cases, a specific therapy has not yet been found, but the vaccine. This has triggered a further series of issues. Who to vaccinate first, how to achieve the so-called "herd immunity", especially if it is right, as it is being done, start with the medical staff and immediately after safeguard the elderly which also involve the problem of a clear explanation and acceptance, through informed consent, which it can be particularly difficult to illustrate.