This phenomenon is called
memory. When an antigen
contact for the first with cells of
the immune system, B
lymphocytes are producers of
specific against that
antigen multiply in days synthesize
their . This is called primary
. Some of these specific
lymphocytes remain in the
for a long time, during the
entire life the individual, and they
the memory cells of
immune system. When the is
exposed in the to the same
antigen production of antibodies will
faster and more intense the
immune systemis already to
reactagainst that antigen. is called
the secondary .