Aluminium hydroxide potentiates a protective Th1 biased immune response against polio virus that allows for dose sparing in mice and rats

Abstract

Background: The development of new low cost inactivated polio virus based vaccines (IPV) is a high priority and will be essential for the complete eradication of polio. Since the aluminium hydroxide adjuvant is widely used in humans we tested this adjuvant with IPV in two models. Our objective was twofold; to examine the IPV dose sparing effect of aluminium hydroxide and how the adjuvant effect of aluminium hydroxide affected the immunity induced by IPV.

Methods: Mice and rats were immunized with IPV formulated with Aluminium hydroxide and subjected to immunological analyses and serum polio virus neutralization titer determination.

Results: Addition of aluminium hydroxide to IPV led to a ten times dose sparing effect compared to IPV alone, measured by virus neutralization titers in serum. Aluminium hydroxide changed the kinetics of the response against IPV leading to a faster and stronger response, which due to IPV induced immune dominance was characterized as a strong Th1-biased cellular/humoral immune response.

Conclusions: The IPV-aluminium hydroxide formulation constitutes a promising vaccine capable of generating strong Th1 immunity against infection with all three serotypes. A phase I/II clinical study was recently initiated.

Keywords: Adjuvant; Dose sparing; Polio; Th1/Th2 cells; Vaccination; Viral infection.