Alternative Methods of Vaccine Delivery: An Overview of Edible and Intradermal Vaccines

Criscuolo, E.; Caputo, V.; Diotti, R. A.; Sautto, G. A.; Kirchenbaum, G. A.; Clementi, N.

To date, there are three commercially available vaccines produced in insect cells for different indications: Cervarix (GSK) for cervical cancer, Flublok (Protein Sciences, now owned by Sanofi Pasteur) for influenza, and PROVENGE (Dendreon) for prostate cancer [58] . Importantly, the baculovirus expression system is not limited only to cultured cells. Insect larvae or pupae can be used for protein production. In the context of edible vaccines using insect larvae or pupae, silkworm Bombyx mori larvae or pupae have been commercially used for the production of recombinant proteins and also as a feasible delivery system for the vaccine [59, 60] . As mentioned above, the baculovirus-silkworm expression system is able to perform cotranslational and posttranslational modifications and also able to produce large amount and multiple proteins. Moreover, since baculovirus is unable to replicate in vertebral animals, it can be considered a GRAS. Furthermore, the presence of protease inhibitors and biocapsule-like fat in the silkworms may protect recombinant proteins from enzymatic digestion in the GIT [23, 61] .