Recent developments in particulate-based vaccines

Vaccines remain a key tool in the defence against major diseases. However, in the development of vaccines a trade off between safety and efficacy is required with newer vaccines, based on sub-unit proteins and peptides, displaying improved safety profiles yet suffering from low efficacy. Adjuvants can be employed to improve their potency, but currently there are only a limited number of adjuvant systems licensed for clinical use. Of the new adjuvants being investigated, particulate systems offer several advantages including: passive targeting to the antigen-presenting cells within the immune system, protection against adjuvant degradation, and ability for sustained antigen release. There has been a range of particulate vaccine delivery systems outlined in recent patents including polymer-based microspheres (which are generally more focused on the use of synthetic polymers, in particular the polyesters) and surfactant-based vesicles. Within these formulations, several patented systems are exploiting the use of cationic lipids which, despite their limitations in gene therapy, clearly offer strong potential as adjuvants. Within this review, the current range of particulate system technologies being investigated as potential adjuvants are discussed with regard to both their respective advantages and the potential hurdles which must be overcome for such systems to be converted into successful pharmaceutical products.

Immune-inspired adaptive information filtering

Adaptive information filtering is a challenging research problem. It requires the adaptation of a representation of a user’s multiple interests to various changes in them. We investigate the application of an immune-inspired approach to this problem. Nootropia, is a user profiling model that has many properties in common with computational models of the immune system that have been based on Franscisco Varela’s work. In this paper we concentrate on Nootropia’s evaluation. We define an evaluation methodology that uses virtual user’s to simulate various interest changes. The results show that Nootropia exhibits the desirable adaptive behaviour.

Vaccines

Vaccines continue to offer the key line of protection against a range of infectious diseases; however, the range of vaccines currently available is limited. One key consideration in the development of a vaccine is risk-versus-benefit, and in an environment of perceived low risk, the benefit of vaccination may not be recognised. To address this, there has been a move towards the use of subunit-based vaccines, which offer low side-effect profiles but are generally weakly immunogenic. This can be compensated for by the development of effective adjuvants. Nanotechnology offers key attributes in this field through the ability of nanoparticulates to incorporate and protect antigens from rapid degradation, combined with their potential to effectively deliver the antigens to appropriate cells within the immune system. These characteristics can be exploited in the development of new adjuvants. This chapter will outline the applications of nanosystems in vaccine formulations and consider the mechanisms of action behind a range of formulations.