Everyone aged 16 and over now needs a "pass vaccinal" to attend large events and for entry to a wide range of venues including bars, restaurants, museums, or to use some types of public transport including planes and long-distance trains.

To qualify for a pass vaccinal you must have:

This “vaccinal effect” was first described more than 15 years ago in cancer research when scientists found that certain monoclonal antibodies can trigger killer T cells to eliminate tumors.

One modification slows the antibody degradation to give it a longer effective life; another improves the so-called vaccinal effect, which summons T cells—another arm of the immune system—to help destroy infected cells.

Or it could be that the antibody treatment has something called a “vaccinal” effect that far outlasts the life of the antibodies.