Dynamics of acute and memory mucosal and systemic immune responses against HIV-1 envelope following immunizations through single or combinations of mucosal and systemic routes

In this study, immunizations at 2 weeks vs. 6 weeks intervals, with an HIV-1 envelope protein in adjuvants, through intra-nasal (IN), intra-muscular (IM), IN followed by IM (IN/IM) and IM/IN, were compared for induction of mucosal and systemic immune responses. IN/IM immunizations at 2, but not at 6, week intervals induced the highest mucosal and systemic immune responses compared to other immunization routes. Following a resting memory phase, IN boosting of IN/IM-immunized mice, compared to IM-boosting of IM-immunized mice, induced increased IgA responses. Thus, depending on the immunization intervals, IN/IM may be more effective than IM immunizations for short- and long-term immunity.