Diseases such as HIV/AIDS, tuberculosis, malaria and cancer are prime targets 
for prophylactic or therapeutic vaccination, but have proven partially or wholly 
resistant to traditional approaches to vaccine design. New vaccines based on 
recombinant viral vectors expressing a foreign antigen are under intense 
development for these and other indications. One of the most advanced and most 
promising vectors is the attenuated, non-replicating poxvirus MVA (modified 
vaccinia virus Ankara), a safer derivative of the uniquely successful smallpox 
vaccine. Despite the ability of recombinant MVA to induce potent humoral and 
cellular immune responses against transgenic antigen in humans, especially when 
used as the latter element of a heterologous prime-boost regimen, doubts are 
occasionally expressed about the ultimate feasibility of this approach. In this 
review, five common misconceptions over recombinant MVA are discussed, and 
evidence is cited to show that recombinant MVA is at least sufficiently 
genetically stable, manufacturable, safe, and immunogenic (even in the face of 
prior anti-vector immunity) to warrant reasonable hope over the feasibility of 
large-scale deployment, should useful levels of protection against target 
pathogens, or therapeutic benefit for cancer, be demonstrated in efficacy 
trials.