Schully KL, Sharma S, Peine KJ, Pesce J, Elberson MA, Fonseca ME, Prouty AM, Bell MG, Borteh H, Gallovic M, Bachelder EM, Keane-Myers A, Ainslie KM. Rapid vaccination using an acetalated dextran microparticulate subunit vaccine confers protection against triplicate challenge by bacillus anthracis.
Pharm Res 2013;
30:1349-61. [PMID:
23354770 DOI:
10.1007/s11095-013-0975-x]
[Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 01/04/2013] [Indexed: 01/20/2023]
Abstract
PURPOSE
A rapid immune response is required to prevent death from Anthrax, caused by Bacillus anthracis.
METHOD
We formulated a vaccine carrier comprised of acetalated dextran microparticles encapsulating recombinant protective antigen (rPA) and resiquimod (a toll-like receptor 7/8 agonist).
RESULTS
We were able to protect against triplicate lethal challenge by vaccinating twice (Days 0, 7) and then aggressively challenging on Days 14, 21, 28. A significantly higher level of antibodies was generated by day 14 with the encapsulated group compared to the conventional rPA and alum group. Antibodies produced by the co-encapsulated group were only weakly-neutralizing in toxin neutralization; however, survival was not dependent on toxin neutralization, as all vaccine formulations survived all challenges except control groups. Post-mortem culture swabs taken from the hearts of vaccinated groups that did not produce significant neutralizing titers failed to grow B. anthracis.
CONCLUSIONS
Results indicate that protective antibodies are not required for rapid protection; indeed, cytokine results indicate that T cell protection may play a role in protection from anthrax. We report the first instance of use of a particulate carrier to generate a rapid protective immunity against anthrax.
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