Smallpox vaccine-induced antibodies are necessary and sufficient for protection against monkeypox virus.

Animal Models & Retroviral Vaccines Section, National Cancer Institute, 41/D804, Bethesda, Maryland 20892, USA.
Nature Medicine (Impact Factor: 28.05). 08/2005; 11(7):740-7. DOI: 10.1038/nm1261
Source: PubMed

ABSTRACT Vaccination with live vaccinia virus affords long-lasting protection against variola virus, the agent of smallpox. Its mode of protection in humans, however, has not been clearly defined. Here we report that vaccinia-specific B-cell responses are essential for protection of macaques from monkeypox virus, a variola virus ortholog. Antibody-mediated depletion of B cells, but not CD4+ or CD8+ T cells, abrogated vaccine-induced protection from a lethal intravenous challenge with monkeypox virus. In addition, passive transfer of human vaccinia-neutralizing antibodies protected nonimmunized macaques from severe disease. Thus, vaccines able to induce long-lasting protective antibody responses may constitute realistic alternatives to the currently available smallpox vaccine (Dryvax).

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