Recent Advances in Nanovaccines Using Biomimetic Immunomodulatory Materials

Vijayan, Veena; Mohapatra, Adityanarayan; Uthaman, Saji; Park, In-Kyu

Very few vaccine candidates have successfully reached the clinic after preclinical evaluations. Most vaccines that are available now in the market can elicit only humoral responses, thereby availing the need for the development of vaccines that can generate strong cellular responses for certain infectious diseases and cancer. One of such biomimetic nanovaccines is "Mosquirix", which was proved to be effective against malaria. This nanovaccine constituted the circumsporozoite protein of Plasmodium falciparum and MPLA 4 with a saponin adjuvant QS-21 [152] . Another nanovaccine, which is currently under clinical trials as "Vaxfectin ® ", is cationic liposomal formulation by encapsulating therapeutic DNA vaccines against the herpes simplex virus type-2 (HSV-2). Vaxfectin ® nanovaccines are also used for DNA immunization against influenza virus H5N1, and are also under clinical trials [153] . Another FDA-approved nanovaccine is Inflexal ® V, where the HA surface molecules of the influenza virus are directly fused with lipid components, and used as a subunit influenza vaccine [154] . Generalized modulus for membrane antigens (GMMA) was derived from the outer membrane of genetically modified gram-negative bacteria. It can produce Penta-acylated lipopolysaccharide, and these vaccines were used against bacterial infection Shigellosis, and are in clinical trials now [155] . In addition to the nanovaccines, as mentioned earlier, Stimuvax ® is another therapeutic liposome vaccine against cancer. It has a lipo-peptide called Tecemotide, which is used as an antigen target specific tumor antigens. However, this vaccine failed in the III phase of clinical trials [156] . Another liposomal therapeutic vaccine, which is a modified form of Stimuvax ® , is currently under clinical trials; this nanovaccine is composed of a synthetic peptide (antigen), an MPLA immunoadjuvant, and lipids [157] . Another biomimetic nanovaccine is Epaxal, a viral liposomal nanovaccine that uses viral glycoprotein fused with lipids as an adjuvant, and that is used against hepatitis A infection [158] .