Influenza vaccines: crossing the translational gap to improve outcomes in the elderly

Immunizations in older adults

Older adults disproportionately sustain morbidity and mortality due to vaccine-preventable illnesses. Despite this observation, adult immunization rates continue to lag behind national goals. Reduced vaccine efficacy in older adults leading to apathy regarding the need for vaccine administration, unrealistic expectations for disease prevention rather than reduced illness severity, and system issues that make vaccine administration and tracking difficult all contribute to this problem. In this review, the biologic and system-based causes for vaccine failure in aged adults are reviewed, issues of efficacy and cost-effectiveness in older adults are summarized for influenza and pneumococcal vaccine, and ways to improve vaccine effectiveness in older adults, now and in the future, are outlined.

Rejection of large HPV-16 expressing tumors in aged mice by a single immunization of VacciMax encapsulated CTL/T helper peptides

The incidence of cancer increases significantly in later life, yet few pre-clinical studies of cancer immunotherapy use mice of advanced age. A novel vaccine delivery platform (VacciMax,VM) is described that encapsulates antigens and adjuvants in multilamellar liposomes in a water-in-oil emulsion. The therapeutic potential of VM-based vaccines administered as a single dose was tested in HLA-A2 transgenic mice of advanced age (48-58 weeks old) bearing large palpable TC1/A2 tumors. The VM-based vaccines contained one or more peptides having human CTL epitopes derived from HPV 16 E6 and E7. VM formulations contained a single peptide, a mixture of four peptides or the same four peptides linked together in a single long peptide. All VM formulations contained PADRE and CpG as adjuvants and ISA51 as the hydrophobic component of the water-in-oil emulsion. VM-formulated vaccines containing the four peptides as a mixture or linked together in one long peptide eradicated 19-day old established tumors within 21 days of immunization. Peptide-specific cytotoxic cellular responses were confirmed by ELISPOT and intracellular staining for IFN-gamma producing CD8+ T cells. Mice rendered tumor-free by vaccination were re-challenged in the opposite flank with 10 million HLF-16 tumor cells, another HLA-A2/E6/E7 expressing tumor cell line. None of these mice developed tumors following the re-challenge. In summary, this report describes a VM-formulated therapeutic vaccine with the following unprecedented outcome: a) eradication of large tumors (> 700 mm3) b) in mice of advanced age c) in less than three weeks post-immunization d) following a single vaccination.