An international research team has demonstrated that a vaccine that stimulates production of anti-HIV antibodies in vaginal tissue can protect monkeys from HIV infection (Bomsel M et al. Immunity. 2011;34:269-280).
Acquisition of HIV through sexual intercourse mainly occurs at mucosal sites, but vaccine strategies under investigation usually aim to induce neutralizing antibodies or cytotoxic T cells circulating in the blood. An alternative vaccine strategy could be to elicit a mucosal immune response to block viral entry at mucosal sites. In this case, researchers sought to elicit IgA antibodies specific for gp41, HIV's most conserved envelope subunit. These antibodies have previously been shown to block HIV infection of mucosal cells.
Hampton T. Mucosal HIV Protection. JAMA. 2011;305(13):1290. doi:10.1001/jama.2011.385