cells quickly initiate an IMMUNE RESPONSEby releas-
ing HISTAMINEand other biochemicals to stimulate
LYMPHOCYTEactivity. This HYPERSENSITIVITY REACTION
results in the common symptoms of ALLERGIC RHINI-
TIS(seasonal allergies). In 2003 the US Food and
Drug Administration (FDA) approved the first nasal
VACCINEfor INFLUENZA(the flu). It was the first to
capitalize on the immune response NALT can gen-
erate to provide systemic (bodywide) IMMUNITYfor
the influenza strains the vaccine contains.
For further discussion of NALT within the con-
text of the structures and functions of the immune
system, please see the overview section “The
Immune System and Allergies.”
See also ALLERGEN; B-CELL LYMPHOCYTE; BRONCHUS-
ASSOCIATED LYMPHOID TISSUE (BALT); COLDS;
MACROPHAGE; MAST CELL; MUCOSA-ASSOCIATED LYM-
PHOID TISSUE (MALT); PATHOGEN; PHAGOCYTE; SKIN-
ASSOCIATED LYMPHOID TISSUE (SALT); SNEEZE;
VASCULAR-ASSOCIATED LYMPHOID TISSUE(VA LT); VIRUS.288 The Immune System and Allergies