Pre-Exposure Vaccination and Biosafety

The Advisory Committee on Immunization Practices recommends routine vaccination with live smallpox vaccine (ACAM2000) for laboratory personnel who directly handle cultures or animals contaminated or infected with:

  • replication-competent vaccinia virus
  • recombinant vaccinia viruses derived from replication-competent vaccinia strains (e.g., inserted foreign gene)
  • other orthopoxviruses that infect humans (e.g., camelpox, cowpox, monkeypox, variola virus)

Vaccination is not recommended for workers that only work with replication-deficient poxvirus strains and vectors.

Laboratory personnel working with replication-competent vaccinia viruses and recombinant viruses developed from replication-competent vaccinia viruses should be revaccinated at least every 10 years. Those who handle more virulent orthopoxviruses (e.g., Monkeypox virus) should be revaccinated every 3 years.

ACAM2000 is the only smallpox vaccine currently recommended by the Advisory Committee on Immunization Practices and is available for nonemergency use in the United States. More information on vaccines, contraindications, and adverse events are available under Vaccine Information.


Biosafety requirements for laboratories engaging in work with Orthopoxviruses (whether replication competent or not) are outlined in Biosafety in Microbiological and Biomedical Laboratories (BMBL).