Viral vaccines rotavirus vaccine

A good example of the recent and future evolution of viral vaccines and their concomitant issues of technology, complexity and competition, is the rotavirus vaccine. This is of great relevance for the prevention of diarrhea, which is often deadly in developing countries (half a million deaths per year) and has high hospitalization costs in rich countries. After successive failures of monovalent vaccines, multivalent vaccines based on the reshuffling of rotavirus strains comprising the attenuation properties of animal strains with the external capsid of human serotypes were developed. 

The majority of experimental vaccines containing ISCOMs as adjuvants have been directed toward viral diseases such as HIV-1, influenza, rotavirus, rabies and measles. Intranasal and oral vaccination using these agents have been variable and disappointing. Intramuscular and subcutaneous administration of these vaccines has produced more consistent results [97]. The complex composition of ISCOMs leads to some difficult isolation and development problems that center on quantitative analysis of their components and product consistency. Moreover, there is no information about the stability of the quillaja saponins incorporated into ISCOMs, which are apparently buffered at pH 7.4 [97]. Thus, it is unclear from many of the reports whether ISCOMs offer any medical or manufacturing advantages over the use of purified saponins alone. 

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