Suppository-mediated DNA immunization induces mucosal immunity against bovine herpesvirus-1 in cattle

Mucosal surfaces are the primary sites for the transmission of infectious a gents including viruses, so effective vaccines generally should induce muco sal immunity. Furthermore, noninvasive delivery is desirable because of the ease of application, the high degree of patient compliance, and the improv ed safety for patents and clinicians due to the elimination of needles. Unf ortunately, most of the conventional vaccines are parenterally administered and result in systemic rather than mucosa[ Immunity. Here we present the f irst report of mucosal immunity by noninvasive DNA immunization in a target species. As an approach to induce mucosal immunity against bovine herpesvi rus-1, cows were immunized intravaginally with suppositories containing pla smid coding for glycoprotein D. Serum IgG, as well as IgA both in the serum and in the nasal fluids, were detected, which supports the contention of a common mucosal immune system. This level of immunity was of sufficient mag nitude to minimize weight loss and significantly reduce the duration of vir us shedding after intranasal viral challenge, which demonstrates the effica cy of suppository-based administration of DNA vaccines to target species. A s this Is a very practical method of delivery, it has great potential to be applied as vaccine or therapy in a variety of species. (C) 2001 Academic P ress.