Intranasal Protollin/F1-V vaccine elicits respiratory and serum antibody responses and protects mice against lethal aerosolized plague infection.

F1-V is a recombinant plague antigen comprising the capsular (F1) and virulence-associated (V) proteins. Given intramuscularly with Alhydrogel, it protects mice against challenge, but is less effective in non-human primates against high-dose aerosolized Yersinia pestis challenge, perhaps because it fails to induce respiratory immunity. Intranasal immunization of mice with F1-V formulated with a Proteosome-based adjuvant (Protollin), elicited high titers of specific IgA in lungs whereas intranasal F1-V alone or intramuscular Alhydrogel-adsorbed F1-V did not.

Design and testing for a nontagged F1-V fusion protein as vaccine antigen against bubonic and pneumonic plague.

A two-component recombinant fusion protein antigen was re-engineered and tested as a medical counter measure against the possible biological threat of aerosolized Yersinia pestis. The active component of the proposed subunit vaccine combines the F1 capsular protein and V virulence antigen of Y. pestis and improves upon the design of an earlier histidine-tagged fusion protein.