Review on Adeno Virus; As a Vaccine Vehicle

Adenoviruses have moved to the forefront of vaccinology and are showing substantial promise as vehicles for antigen delivery for a number of vaccines currently being developed. Most studies to date have focused on human serotype adenoviruses, particularly human adenovirus type 5. Human serotype adenovirus vaccine vectors are particularly useful for development of veterinary vaccines as neutralizing antibodies to the vector will not usually be present in the vaccinates. Most vectors currently used as vaccine carriers are deleted in E1 gene. The original E1 deleted adenoviral vectors were constructed by homologous recombination. Replication incompetent vectors contain an antigen expression cassette substituted for the deleted E1A– E1B region. These replication incompitant adenoviruses can not replicate because of the deletion of the essential viral E1 gene region containing two genes. Replication competent adenoviral vectors encode all of the remaining adenoviral antigens in addition to the transgene product, i.e., the vaccine antigen. The potential for adenoviruses to elicit powerful B cell and T cell responses in the mammalian host are the main reason for the use of these vectors in vaccine development. For effective veterinary use, extensive research on adenoviral vaccine vectors should be undertaken.