DNA vaccines might offer an alternative to the live smallpox vaccine in providing protective efficacy in an orthopoxvirus (OPV) lethal respiratory challenge model. BALB/c mice were immunised with DNA vaccines coding for 10 different single vaccinia virus (VACV) membrane proteins. After an intranasal challenge with the VACV IHD strain, three gene candidates B5R, A33R and A27L produced ≥66% survival. The B5R DNA vaccine consistently produced 100% protection and exhibited greatest efficacy after three 50 g intramuscular doses in this model. Sero-conversion to these vaccines was often inconsistent, implying that antibody itself was not a correlate of protection. The B5R DNA vaccine induced a strong and consistent gamma interferon (IFN␥) response in BALB/c mice given a single DNA vaccine dose. Strong IFN␥ responses were also measured in pTB5R immunised C57BL6 mice deficient for MHC class I molecules, suggesting that the memory response was mediated by a CD4 + T cell population. Crown
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.