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Vaccinia Virus Biological Agent Reference Sheet (BARS)

Updated January 12, 2024

Disclaimer: Risk group, biosafety level, and all other precautions noted here are subject to change after a risk assessment by EHS.


Agent Type Risk Group Biosafety Level Animal Housing Biosafety Level
Virus RG-2 BSL-2 ABSL-2

Agent Characteristics 

Risk Group: RG-2 associated with human disease, rarely serious; preventive or therapeutic interventions often available.

Agent Type: Virus 


The Vaccinia Virus (VACV) is a linear, double-stranded DNA virus in the Poxviridae family. It played a crucial role in eradicating smallpox in the late 1970s through vaccination. When used for inoculation, VACV typically causes localized skin lesions that heal in about 10-14 days. Accidental infection can occur through contact with the vaccination site and broken skin. VACV is the prototype of the Orthopoxvirus genus, which includes poxviruses that infect humans, such as variola virus (causing smallpox), mpox virus, and cowpox virus. Multiple VACV strains vary in virulence for humans and animals. "Standard" VACV was historically used for smallpox immunization and continues to be used for this purpose. It can replicate in human cells, posing a risk of serious infection. Laboratory strains like the New York City Board of Health (NYCBOH) strain (Western Reserve or WR) and non-attenuated parental VACV strains also carry risks for laboratory personnel. Highly attenuated, host-restricted poxviruses like modified vaccinia Ankara (MVA), NYVAC, ALVAC, and TROVAC are used for recombinant vaccine development and are typically less pathogenic.

Host Range: Several mammals, including humans, rabbits, cows and river buffalo.

Host Shedding: Direct contact                   Incubation Period: 10-14 days

Route of Exposure to Humans: Direct contact, Mucous Membranes, Ingestion, Percutaneous, Broken skin

Infectious Dose: Unknown. Vaccine titer is usually 10^8 pock-forming units per mL.

Health Hazards

Signs and symptoms of infection may include:

  • Flu-like symptoms (i.e., fever, headache, dehydration, weight loss, lethargy)
  • Cutaneous symptoms (i.e., skin lesions, rash)
  • Lymphoreticular symptoms (i.e., enlarged internal organs or lymph nodes)

Immunizations: Available                         Prophylaxis*: None available

The JYNNEOS vaccine is recommended as an alternative to ACAM2000 for primary vaccination and booster doses for laboratory and health care personnel at risk for occupational exposure to orthopoxviruses, including those handling more virulent strains like Variola or Monkeypox viruses.

*Formal medical advice is obtained during medical consultations with Cornell Health or a primary healthcare provider as needed.

Agent Viability 

Survival Outside Host Disinfection Inactivation

The dried virus can survive up to 39 weeks at 6.7% moisture and 4ºC.

Bleach 1:10 for 30 minutes 

Quarternary ammonium combined with chlorhexidine or glutaraldehyde. 

The virus is inactivated by dry heat at 95 ºC for 2 hours. The heat-sensitive fraction of the virus is inactivated by moist heat at 60 ºC, while the heat-resistant fraction may take higher temperatures to fully inactivate it. The virus in its aerosol form is also sensitive to UV light (254 nm).

For more guidance on disinfection, see:  disinfectant selection.

Laboratory Hazards 

  • High energy-creating activities (centrifugation, sonication, high pressure systems, vortexing, tube cap popping)
  • Handling of sharps (needles, scalpels, microtome blades, broken glass, etc.)
  • Splash/droplet-creating activities (shaking incubators, liquid culturing, mechanical pipetting)
  • Equipment contamination
  • Exposed skin/uncovered wounds

Laboratory Acquired Infection (LAI) History: Unknown

Laboratory Handling Guidelines 

Laboratory Biosafety Level (BSL): BSL-2

Attenuated Strain Alternatives: Ankara (MVA) strain VACV Western Reserve NYVAC


Lab Engineering Controls Personal Protective Equipment
  • Eye protection
  • Single gloves
  • Additional gloves (recommended)
  • Snap-front lab coat with cinch cuffs (lab work)
  • Additional mucous membrane protection (mask/face shield)

For personnel at risk for orthopoxvirus exposure, JYNNEOS is an alternative to ACAM2000 for primary vaccination and boosters. Booster doses with JYNNEOS are recommended every 2 years for those handling more virulent orthopoxviruses and every 10 years for less virulent viruses.

Waste Management: Regulated Medical Waste (RMW)

Shipping Guidance: Refer to EHS Biological Materials Shipping 

Animal Vivarium Guidance

Animal Housing Biosafety Level (ABSL): ABSL-2

Animal Biosecurity: Experimental animals are housed separately

Perform InoculationsBiosafety Cabinet

Change CagesBiosafety Cabinet

Exposure and Spill Procedures 

Mucous Membranes: Flush eyes, mouth, or nose for 15 minutes at an eyewash station. See: responding to exposures.

Other Exposures: Wash with soap and water for 15 minutes (open wounds, sores, etc.) or a minimum of 20 seconds for areas with intact skin. See:  responding to exposures.

Small Spills: Notify others working in the lab. Evacuate area and allow 30 minutes for aerosols to settle. Don appropriate PPE. Cover area of the spill with paper towels and apply disinfectant, working from the perimeter toward the center. Allow 30 minutes of contact time before disposal and cleanup of spill materials. See:  spill cleanup

Large Spills: Request assistance from the EHS Spill Team by calling CUPD dispatch. Call 911 from a campus phone or 607-255-1111 from a mobile phone.

Incident Reporting: Immediately report the incident to the supervisor and complete the EHS online injury/illness report as soon as possible. Incidents with genetically modified vaccinia will be reported to the NIH through the biosafety officer or IBC.

Medical Follow-Up:

  • For students, seek medical attention at Cornell Health or local primary care provider. Call Cornell Health at 607-255-5155 (24-hour phone consultation line) or a local urgent care. 
  • For faculty and staff, seek medical evaluation with a local primary care provider or urgent care. Cornell Health does not see employees for post-exposure care. 
  • Emergencies: Call 911 from a campus phone or 607-255-1111 from a mobile phone. 
Cornell EHS would like to thank Emory University for using their Biological Agent Reference Sheet (BARS) format and some content. 

More Information


  1. Jacobs BL, Langland JO, Kibler KV, et al. Vaccinia virus vaccines: past, present and future. Antiviral Res. 2009;84(1):1–13.
  2. CDC. (2020). Biosafety in Microbiological and Biomedical Laboratories. Retrieved from CDC.
  3. Public Health Agency of Canada. Vaccinia Virus. Pathogen Safety Data Sheets: Infectious Substances.
  4. MacNeil, A., Reynolds, M. G., & Damon, I. K. (2009). Risks associated with vaccinia virus in the laboratory. Virology, 385(1), 1–4.
  5. Mempel, M., Isa, G., Klugbauer, N., Meyer, H., Wildi, G., Ring, J., Hofmann, H. (2003). Laboratory Acquired Infection with Recombinant Vaccinia Virus Containing an Immunomodulating Construct. Journal of Investigative Dermatology, 120(3), 356–358.
  6. Whitehouse, E. R., Rao, A. K., Yu, Y. C., Yu, P. A., Griffin, M., Gorman, S., … Petersen, B. W. (2019). Novel Treatment of a Vaccinia Virus Infection from an Occupational Needlestick — San Diego, California, 2019. MMWR. Morbidity and Mortality Weekly Report, 68(42), 943–946.
  7. de Oliveira TM, Rehfeld IS, Coelho Guedes MI, Ferreira JM, Kroon EG, Lobato ZI. Susceptibility of Vaccinia virus to chemical disinfectants. Am J Trop Med Hyg. 2011;85(1):152-157. doi:10.4269/ajtmh.2011.11-0144