|UDDOWLA, SABENA - Oak Ridge Institute For Science And Education (ORISE)|
|HOLLISTER, JASON - National Institutes Of Health (NIH)|
|Pacheco Tobin, Juan|
|Rieder, Aida - Elizabeth|
Submitted to: Journal of Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/9/2012
Publication Date: 8/22/2012
Citation: Uddowla, S., Hollister, J., Pacheco Tobin, J., Rodriguez, L.L., Rieder, A.E. 2012. A safe foot-and-mouth disease vaccine platform with two negative markers for differentiating infected from vaccinated animals (DIVA). Journal of Virology. Nov,86(21):11675-11685.
Interpretive Summary: Vaccination of domestic animals with chemically inactivated Foot-and-Mouth Disease Virus (FMDV) is widely practiced to control FMD. Current vaccine production technology requires; growing large volumes of virulent virus that is then chemically inactivated to remove infectivity and purification to remove undesirable proteins. This process poses the risk of release of infectious virus from production plants, as illustrated by the accidental FMDV outbreak in the United Kingdom in 2007. In this study, we describe the development of a safe production platform for inactivated vaccines that consists of a genetically engineered FMDV lacking a protein (L) that renders the virus not virulent and not transmissible in cattle and swine. This attenuated virus platform has built in markers that allow easy differentiation of infected from vaccinated animals (DIVA) using a companion ELISA test, a critical feature during eradication campaigns. Inactivated vaccine prepared with this platform provides full protection to vaccinated animals from challenge with homologous virulent FMDV. The platform also includes a feature that allows for rapid development specific vaccines against newly emerging field strains addressing the great genetic diversity of FMDV. This new platform represents one of the most important innovations in FMD vaccine production in decades and will allow safe production of vaccines to help in the global control and eventual eradication of this devastating disease.
Technical Abstract: Vaccination of domestic animals with chemically inactivated Foot-and-Mouth Disease Virus (FMDV) is widely practiced to control FMD. Currently, FMD vaccine manufacturing requires the growth of large volumes of virulent FMDV in bio-containment level facilities. Here, two marker FMDV vaccine candidates (A24LL3DYR and A24LL3BPVKV3DYR) featuring the deletion of the leader coding region (L^pro) and one of the 3B proteins were constructed and evaluated. These vaccine candidates also contain either one or two sets of mutations to create negative antigenic markers in the 3D polymerase (3D^pol) and 3B non-structural proteins. Mutations spanning residues H27N31 in 3D^pol and RQKP9-12 to PVKV substitutions in 3B2 abolish reactivity with monoclonal antibodies targeting the respective sequences in 3D^pol and 3B. The marker viruses also encode unique restriction endonuclease sites flanking the capsid-coding region that allow for easy derivation of custom designed vaccines. In contrast to the parental A24WT, single A24LL3DYR and double A24LL3BPVKV3DYR mutant viruses were markedly attenuated upon inoculation of cattle using the natural aerosol or direct tongue inoculation. Likewise, pigs inoculated with live A24LL3DYR virus in the heel bulbs showed no clinical signs of disease, no fever, and no FMD transmission to in-contact animals. Immunization of cattle with chemically inactivated A24LL3DYR and A24LL3BPVKV3DYR vaccines provided 100 percent protection from challenge with parental wild-type (WT) virus. These attenuated, antigenically-marked viruses provide a safe alternative to virulent strains for FMD vaccine manufacturing. In addition, a competitive enzyme-linked immunosorbent assay (cELISA) targeted to the negative markers provides a suitable DIVA companion test.