Vaccine Vectors
Attenuated vaccine vectors are live bacteria or viruses that have been weakened such that they are no longer capable of causing disease. These attenuated vectors can be used as vaccines themselves or as a general delivery system that can be used to develop vaccines against a variety of diseases. Emergent BioSolutions has developed two universal vaccine delivery vectors: the Salmonella typhi spi-VEC™ bacterial platform suitable for oral vaccine delivery, and a Modified Vaccinia Ankara (MVA) viral vector MVAtor™ (Viral Vaccine Vector) for injectable vaccines.

MVAtor^TM Description
MVAtor is intended to share the beneficial properties of an MVA strain formerly used as a smallpox pre-vaccine designed to avoid any potential risk of Bovine Spongiform Encephalitis (BSE). Emergent BioSolutions has licensed the formerly used pre-vaccine. MVAtor is proprietary to Emergent BioSolutions.

MVA as a Vector
Recombinant MVA vectors are among the most promising live viral vector systems, because of their safety profile and their versatility for the production of heterologous proteins.² Evidence regarding the concurrent avirulence of MVA for laboratory animals and its use for primary smallpox vaccination in more than 100,000 humans founded a safety profile for recombinant MVA that, depending on the nature of the inserted target gene, can allow the recombinant MVA to be used under conditions of biosafety level 1. ^1.2 In animal models, MVA vaccines have been found immunogenic and protective against various infectious agents including immunodeficiency viruses, influenza, parainfluenza, measles virus, flavivirus, or plasmodium parasites.¹

MVA History
MVA was developed in Germany through a process of hundreds of serial passages of vaccinia virus in chicken cells, thus losing more than 10% of the original genome and the ability to replicate in human cells.

References
¹ Sutter/Staib, Current Drug Targets Infectious Disorders 2003, Bentham Science Publishers Ltd, p.1

² Drexler et al., Current Opinion in Biotechnology 2004, 15:506–512, p.1

MVAtor is a registered trademark in Germany, a pending trademark in the European Community and is owned by Emergent.

spi-VEC is a trademark registered in the European Community and owned by Emergent.