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

Nat Med. 2005 Jul;11(7):740-7. doi: 10.1038/nm1261. Epub 2005 Jun 12.


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).

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antibodies / immunology
  • Antibody Formation
  • B-Lymphocytes / immunology*
  • CD4-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / immunology
  • Immunologic Memory
  • Macaca mulatta
  • Monkeypox / immunology*
  • Monkeypox / prevention & control
  • Monkeypox virus / immunology*
  • Smallpox Vaccine / immunology*


  • Antibodies
  • DryVax vaccine
  • Smallpox Vaccine