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 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.