114 VLPs and particle vaccines

VLPs represent a powerful tool for vaccine development, representing the closest strategy to the native viruses for displaying and delivering conformational epitopes, with improved induction of antibodies and immune response in its whole. Moreover, the lack of genetic material makes VLPs the “safer counterpart” of live attenuated or killed viral vaccines which, indeed, may induce limited but possible undesired effects. VLP-based vaccines have been developed from both enveloped and non-enveloped viruses to target infectious and non-infectious diseases and are in various stages of development spanning preclinical evaluation to market. In particular, the only 2 preventive cancer vaccines licensed are based on VLP approach (HBV and HPV vaccines). Overall, pre-clinical and clinical trials with different VLP-based vaccines have shown they are well tolerated and can be administered by a number of routes, including intramuscular, subcutaneous, oral or intranasal. VLP vaccines have also been demonstrated to be highly immunogenic and capable of stimulating protective immunity in a number of instances when administered with or without adjuvants. Their potent immunogenicity is a result of several factors, including the ability to incorporate key immunogenic properties of viruses into a single entity and to hit the cells relevant for initiate an effective adaptive immune response.