Currently, the fight against poliomyelitis disease is carried out through the use of the Sabin oral polio vaccine (OPV) a live attenuated vaccine that has allowed an almost total eradication of the disease.
However, this type of vaccine lays serious side effects when not handled according to the manufacturer’s instructions. The main risk is the de-attenuation of the attenuated virus, which causes vaccine-associated paralytic poliomyelitis. Elimination of this risk is desirable for the patients. A feasible proposal is the use of an inactivated vaccine; however, as the biological activity of the attenuated virus is lost, the immunogenicity of the antigen is reduced, thus requiring a much larger amount of antigen to induce immunity. One solution to this technical problem is the use of saponin-based adjuvants as studied by de Costa et al. (2014). This technology allows to increase the immunogenicity of the attenuated vaccine, conceding a reduction of the antigen dosage, and therefore a decrease in the production cost. All of the above makes possible the access to an inactivated vaccine without risk of de-attenuation for the population of developing countries in which the infection with poliovirus still has a significant prevalence.
In this case (de Costa, y otros, 2014), the results of correlates of immune protection show that the addition of saponin-based adjuvants to inactivated poliovirus produces an antibody immune response and a Th1 immune response profile.
This trial is a pilot preclinical study. It is highly probable that this type of Th1 profile and intense IgG response will be protective in subsequent vaccination and infection experiments.
The data from this first study show a first glimpse of the feasibility of developing an inactivated polio vaccine with a saponin-based adjuvant.
In collaboration with Tulane University, Q-VANT Biosciences participates to the development of a promising new platform for oral vaccines that could be used to prevent a variety of infectious diseases, including poliomyelitis.
References
1. De Costa el al., 2014. Alternative Inactivated Poliovirus Vaccines Adjuvanted with Quillaja brasiliensis or Quil-A Saponins Are Equally Effective in Inducing Specific Immune Responses. PLoS One, 9(8).
