Nanocarriers possessing components with different rates of release

A composition comprising:

• synthetic nanocarriers that comprise:
• (a) an immunomodulatory agent coupled to the synthetic nanocarrier;
• and
• (b) an antigen coupled to the synthetic nanocarrier;
• wherein the immunomodulatory agent and antigen dissociates from the synthetic nanocarrier according to the following relationship:
• IA(rel) %/A(rel) %≧1.2
• wherein IA(rel) % is defined as a weight of immunomodulatory agent released upon exposure of the synthetic nanocarrier to an in vitro aqueous environment at a pH=4.5 for 24 hours divided by the sum of the weight of immunomodulatory agent released upon exposure of the synthetic nanocarrier to an in vitro aqueous environment at a pH=4.5 for 24 hours plus a weight of immunomodulatory agent retained in the synthetic nanocarrier upon exposure of the synthetic nanocarrier to an in vitro aqueous environment at a pH=4.5 for 24 hours, expressed as weight percent, and taken as an average across a sample of the synthetic nanocarriers;
• and
• wherein A(rel) % is defined as a weight of antigen released upon exposure of the synthetic nanocarrier to an in vitro aqueous environment at a pH=4.5 for 24 hours divided by the sum of the weight of antigen released upon exposure of the synthetic nanocarrier to an in vitro aqueous environment at a pH=4.5 for 24 hours plus a weight of antigen retained in the synthetic nanocarrier upon exposure of the synthetic nanocarrier to an in vitro aqueous environment at a pH=4.5 for 24 hours, expressed as weight percent, and taken as an average across a sample of the synthetic nanocarriers.