Browse by author
Lookup NU author(s): Dr Andrei Soliakov, Professor Jeremy LakeyORCiD
Aluminum salts are the most widely used vaccine adjuvants, and phosphate is known to modulate antigen-adjuvant interactions. Here we report an unexpected role for phosphate buffer in an anthrax vaccine (SparVax) containing recombinant protective antigen (rPA) and aluminum oxyhydroxide (AlOH) adjuvant (Alhydrogel). Phosphate ions bind to AlOH to produce an aluminum phosphate surface with a reduced rPA adsorption coefficient and binding capacity. However, these effects continued to increase as the free phosphate concentration increased, and the binding of rPA changed from endothermic to exothermic. Crucially, phosphate restored the thermostability of bound rPA so that it resembled the soluble form, even though it remained tightly bound to the surface. Batches of vaccine with either 0.25 mM (subsaturated) or 4 mM (saturated) phosphate were tested in a disease model at batch release, which showed that the latter was significantly more potent. Both formulations retained their potency for 3 years. The strongest aluminum adjuvant effects are thus likely to be via weakly attached or easily released native-state antigen proteins.
Author(s): Watkinson A, Soliakov A, Ganesan A, Hirst K, LeButt C, Fleetwood K, Fusco PC, Fuerst TR, Lakey JH
Publication type: Article
Publication status: Published
Journal: Clinical and Vaccine Immunology
Year: 2013
Volume: 20
Issue: 11
Pages: 1659-1668
Print publication date: 01/11/2013
Online publication date: 28/08/2013
Acceptance date: 16/08/2013
Date deposited: 13/08/2014
ISSN (print): 1556-6811
ISSN (electronic): 1556-679X
Publisher: American Society for Microbiology
URL: http://dx.doi.org/10.1128/CVI.00320-13
DOI: 10.1128/CVI.00320-13
Altmetrics provided by Altmetric
