Alphavirus-Based Vaccines

Lundstrom, Kenneth

The potential of alphaviruses causing global epidemics has placed additional concern on the needs of addressing biosafety issues. Generally, the strains used for vaccine development are attenuated. Furthermore, in the case using alphavirus particles, second generation helper vectors [126] or split helper systems [8] have been applied to prevent any production of wild-type-like replication-proficient particles through non-homologous recombination. Only recently alphavirus-based vaccines have been subjected to clinical trials. In this context, SFV vectors have been used for delivery of immunostimulatory genes. Furthermore, immunizations for the treatment of CMV and vaccinations against prostate and metastatic cancers have been conducted with alphavirus vectors and particles. The strength of applying alphaviruses is the generation of rapid transgene expression and the transient nature of expression. However, the full potential of alphavirus-based vaccines has not been explored yet. In the future, it is anticipated that additional, positive observations, particularly in the form of providing protection against challenges with lethal pathogens and tumors, will attract the enhanced application of alphaviruses for vaccine development.