Enhanced immune responses and resistance against infection in aged mice conferred by Flu-ISCOMs vaccine correlate with up-regulation of costimulatory molecule CD86.

Ageing is associated with a decline in immune function and our primary objective is to 'reverse' age-related decline in protective immune responses to vaccination by formulating vaccines in appropriate delivery systems. In this paper, we demonstrate that influenza vaccine formulated as ISCOMs is highly immunogenic and confers protection in aged mice, when compared to current influenza vaccine. The enhanced protection conferred by Flu-ISCOMs in aged mice correlates with the up-regulation of co-stimulatory molecule, CD86 (B7.2) and to a lesser extent, CD80 (B7.1) expression on antigen presenting cells.