The novel adjuvant dmLT promotes dose sparing, mucosal immunity and longevity of antibody responses to the inactivated polio vaccine in a murine model

We found that non-adjuvanted ID delivery was not superior to IM delivery for fractional dose sparing, but was associated with development of mucosal immunity. Vaccination with IPV + dmLT promoted serum anti-PV neutralizing antibodies with fractional IPV doses by either IM or ID delivery, achieving at least five-fold dose sparing above non-adjuvanted fractional doses. These responses were most noticeable with the PV1 component of the trivalent vaccine. dmLT also promoted germinal center formation and longevity of serum anti-PV neutralizing titers. Lastly, dmLT enhanced mucosal immunity, as defined by fecal and intestinal anti-PV IgA secretion, when included in IPV immunization by ID or IM delivery. These studies demonstrate that dmLT is an effective adjuvant for either IM or ID delivery of IPV. Inclusion of dmLT in IPV immunizations allows antigen dose sparing and enhances mucosal immunity and longevity of anti-PV responses.