Modified Vaccinia Virus Ankara (MVA)

Download Modified Vaccinia Virus Ankara PDF



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.

Growth Conditions

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.

Health Hazards

Host Range

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.  

Modes of Exposure

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

Signs and Symptoms

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

Infection Dose

MVA is not infectious.


Medical Precautions/Treatment


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.

Diagnosis & Treatment

MVA is not infectious.



Emory Requirements



Laboratory Hazards

Sources  MVA exposure in the laboratory may occur by needlesticks, splashes, etc.

Supplemental References



Biosafety in Microbiological and Biomedical Laboratories, 6th Edition


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.

Spill Procedures


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).

Exposure Procedures

Mucous membrane

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

Other Exposures

Wash area with soap and water for 15 minutes.


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

Seek Medical 

7:30 am - 4:00 pm (OHS):


After Hours:

OIM NP On Call

404-686-5500, PIC# 50464

Needle Stick:

EUH (404-686-8587)

EUHM (404-686-2352)

ENPRC: Maureen Thompson

Office (404-727-8012)

Cell (404-275-0963)



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.

Survival Outside Host

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

Personal Protective Equipment (PPE)

Minimum PPE Requirements

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

Additional Precautions

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

Permit Requirements


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