Modified Vaccinia Virus Ankara (MVA)

MVA is enveloped with a highly asymmetric structure (ellipsoidal, brick-shaped, or barrel-shaped) measuring approximately 360 × 270 × 250 nm, with a single, linear dsDNA genome of 178 kb.

BHK-21 [C-13] fibroblasts isolated from the kidney of an uninfected golden hamster are commonly used. The cells are incubated at 37°C with 5% CO₂ in air atmosphere.

In embryonic chicken tissues: The liver is the major target organ, macrophages and hematopoietic cells are the primary target cells, and chorioallantoic membrane is the major site of replication. However, increasing doses of MVA do not result in increased lesion severity or embryonic death, and MVA-based vaccines are promising for the protection of parrots against avian bornavirus. In mammalian species: MVA is replication-deficient in most mammalian cells, but some mammalian cell lines support limited MVA replication (e.g., human embryonic kidney (HEK) 293 cells, HeLa cells, human Caco-2 cells, Chinese hamster ovary (CHO) cells, and BHK-21 cells).

    Special Precautions 

1) MVA can productively infect human Caco-2 cells after multiple serial passages. 2) Recombination can occur in vitro between MVA vectored vaccine and wild type cowpox virus (CPXV) in cell lines that are semi-permissive to MVA. 3) Nonreplicating MVA enters target cells where recombinant constructs are translated, so risks associated with recombinant constructs must be evaluated on a case-by-case basis. 4) Strains should be evaluated for homogeneity by PCR, sequencing, or infection studies to ensure there are no variants present that can replicate in otherwise resistant mammalian cells.  

Exposure may occur by contact with mucous membranes, ingestion, inhalation of viral particles, and injection.

In rare cases, exposure to MVA may cause serious allergic reactions including difficulty breathing, dizziness, or swelling of the face and neck.

MVA is not infectious.

MVA is not infectious, so prophylaxis is not required.

Vaccination is not required for individuals working in laboratories with only replication-deficient strains of vaccinia virus.

MVA is not infectious.

None

None

Supplemental References

CDC

https://www.cdc.gov/vaccinesafety/vaccines/Smallpox-Vaccine.html

CDC

Biosafety in Microbiological and Biomedical Laboratories, 6^th Edition

Viruses

Okeke MI, Okoli AS, Diaz D, et al. Viruses. 2017 Nov; 9(11): 318

BMC Infect Dis.

Eggers M, Eickmann M, Kowalski K, Zorn J, Reimer K. BMC Infect Dis. 2015 Sep 17;15:375

BSL2 practices should be followed. Inoculated animals shed MVA during the first few hours and should remain at ABSL-2 for 72h, then moved to ABSL1.

Notify others in the area and allow 30 minutes for aerosols to settle. Don appropriate PPE. Cover the spill with paper towels and apply disinfectant effective against MVA, working from the perimeter towards the center. Allow 30 minutes of contact time before disposal and cleanup of spill materials.

Contact Emory’s Biosafety Officer (404-357-1821) or

The Spill Response Team (404-727-2888).

Flush eyes, mouth, or nose for 15 minutes at an eyewash station.

Wash area with soap and water for 15 minutes.

Report the incident to the supervisor and complete an employee incident report in PeopleSoft.

1) 1:10 dilution of bleach (5.25% sodium hypochlorite) for 30 minutes or overnight.

2) quaternary ammonium compounds (QACs)

3) povidone-iodine hand wash and hand rub products

Inactivated by heat (55 °C for 1 h) and disinfectants.

Poxviruses have resistance to drying and may remain viable over several months depending on temperature.

Wear gloves, closed-toed shoes, a lab coat, and appropriate face and eye protection. 

Use respiratory protection if work will be performed outside a biosafety cabinet.

Importing MVA requires a VS 16-6A import permit. You should confirm import requirements with the USDA and your state's Department of Agriculture.