Scientific Publications by FDA Staff

J Immunol 2006 Aug 15;177(4):2552-64

Subunit recombinant vaccine protects against monkeypox.

Heraud JM, Edghill-Smith Y, Ayala V, Kalisz I, Parrino J, Kalyanaraman VS, Manischewitz J, King LR, Hryniewicz A, Trindade CJ, Hassett M, Tsai WP, Venzon D, Nalca A, Vaccari M, Silvera P, Bray M, Graham BS, Golding H, Hooper JW, Franchini G

Franchini G, NCI, Anim Models & Retroviral Vaccines Sect, Bldg 41,Room D-804, Bethesda, MD 20892 USA NCI, Anim Models & Retroviral Vaccines Sect, Bethesda, MD 20892 USA So Res Inst, Frederick, MD 21701 USA Adv BioSci Labs, Kensington, MD 20895 USA NIAID, Vaccine Res Ctr, Bethesda, MD 20892 USA US FDA, Ctr Biol Evaluat & Res, Bethesda, MD 20892 USA Med Univ Bialystok, Dept Gen & Expt Pathol, Bialystok, Poland NCI, Biostat & Data Management Sect, Bethesda, MD 20892 USA USA, Med Res Inst Infect Dis, Ft Detrick, MD 21702 USA NIAID, Biodef Clin Res Branch, Bethesda, MD 20892 USA

The smallpox vaccine Dryvax, a live vaccinia virus (VACV), protects against smallpox and monkeypox, but is contraindicated in immunocompromised individuals. Because Abs to VACV mediate protection, a live virus vaccine could be substituted by a safe subunit protein-based vaccine able to induce a protective Ab response. We immunized rhesus macaques with plasmid DNA encoding the monkeypox orthologs of the VACV L1R, A27L, A33R, and B5R proteins by the intradermal and i.m. routes, either alone or in combination with the equivalent recombinant proteins produced in Escherichia coli. Animals that received only DNA failed to produce high titer Abs, developed innumerable skin lesions after challenge, and died in a manner similar to placebo controls. By contrast, the animals vaccinated with proteins developed moderate to severe disease (20-155 skin lesions) but survived. Importantly, those immunized with DNA and boosted with proteins had mild disease with 15 or fewer lesions that resolved within days. DNA/protein immunization elicited Th responses and binding Ab titers to all four proteins that correlated negatively with the total lesion number. The sera of the immunized macaques recognized a limited number of linear B cell epitopes that are highly conserved among orthopoxviruses. Their identification may guide future efforts to develop simpler, safer, and more effective vaccines for monkeypox and smallpox.