Researchers have created synthetic nanoparticles that greatly bolster vaccine responses by targeting lymph nodes, where most immune reaction occurs. Currently, all other adjuvants (compounds added to boost the shots) are believed to bolster immunity at the site where the vaccine is injected rather than going to the lymph nodes. The mice based study shows the delivery path can be directed to the lymph nodes. Duke University Medical Centre researchers based their strategy on their observation that the skin's mast cells that fight infections also communicate directly with the lymph nodes by releasing nanoparticles (granules), the journal Nature Materials reports. "Our strategy is unique because we have based our bioengineered particles on those naturally produced by mast cells, which effectively solve the same problem we are trying to solve of combating infection," said Ashley St. John, researcher at the Duke's Program in Emerging Infectious Diseases. The synthetic granules when injected, mimic the attributes of the granules found in natural cells, and the synthetic particles also target the draining lymph nodes and provide for the timed release of the encapsulated material, according to a Duke statement. Traditional vaccine adjuvants may help antigens (the small part of a pathogen that is injected during vaccination that the body reacts to) to persist so the body can have an immune reaction and build antibodies so that when a real pathogen, such as the flu virus arrives, it will be conquered.