The lymphocytes B report or Lbm derive from the lymphocytes B. After recognition of the Antigen S by the lymphocytes B (at the time of the primary immunizing response), some are different in lymphocytes B report and from other in Plasmocyte S. Lbm have as a role to memorize the properties of the antigen having activated them, in order to create a faster, longer, more intense and more specific immunizing response in the event of one second infection by this same antigen (secondary immunizing response). Moreover, Lbm have one lifespan much longer than the plasmocytes.

It is on the principle of this immunizing memory that the vaccines are carried out. But the role of these cells is not however clear, the number of these last, does not seem, not to vary to him during time contrary to the specific rate of anticops.

This characteristic of the specific Immunizing response was recognized there is 2400 years by the Greek historian Thucydide of Athens which noticed that “no one did not suffer from the plague twice”.