Local immune responses following nasal delivery of an adjuvanted influenza vaccine.

A key barrier to producing effective nasal immunisations is the low efficiency of uptake of vaccines across the nasal mucosa. Using a recently developed cannulation system, we examined the antibody response induced by nasal immunisation with an ISCOMATRIX influenza vaccine. This showed for the first time, that following nasal vaccination, specific antibodies enter the circulation of primed animals via the draining lymphatics as a wave that peaks approximately 5-6 days after vaccination. These antibodies included some of the IgA isotype and possessed functional haemagglutination inhibition activity. These responses, though small, were induced using a very simple delivery system, emphasising the applicability of this cannulation model for evaluation of excipients and adjuvants aimed at improving intranasal vaccine efficacy.