Recombinant Adeno-Associated Vectors (rAAV)

Prepared by: Michael J. Huerkamp, DVM, Diplomate ACLAM
Date: January 11, 2000

Agent: Recombinant Adeno-Associated Vectors (rAAV)

These agents are non-replicating and are made in the laboratory. They may be injected into the brains, muscle or other tissue of live animals, particularly rodents or nonhuman primates. The protein coat from an adenovirus may be used to coat DNA so that the DNA is absorbed into the nucleus of a mammalian cell.

Potential Hazard: The rAAV itself poses little risk to humans, but helper viruses used in the laboratory to prepare the rAAV may contaminate the rAAV that is to be given to an animal. These helper viruses may recombine with organisms present in the animal and create a new pathogen. Thus, the rAAV itself with contaminating helper virus may pose a risk to humans if the human contacts or ingests the rAAV preparation or excreted rAAV or helper virus and recombination occurs with a human pathogen (such as Herpes simplex virus). Animals given rAAV could be the host for a recombination of the helper virus with a virus present in the animal and a new pathogen could be developed. These risks are low, but possible.

Recommended Precautions: The animal biosafety level II practices (DAR SOP 400-3) will protect husbandry personnel against exposure or infection from rodents or their excreta. ABSL2 containment is not required if vector preparations are assayed and shown to be free of detectable helper virus.

Contrary to standard BSL2 precautions, rodents given rAAV may be maintained in the same colony as uninfected rodents, but must be kept in filter top cages and soiled cages and bedding must be autoclaved before washing. In cases where feeding or cage changing are done in a room without a laminar air flow biosafety cabinet, cage-changing and handling practices must be specifically approved by the Biosafety Committee and personnel must wear protective goggles in addition to PPE described in DAR SOP 400-3. The nonhuman primate biosafety level II practices (DAR SOP 400-16) will protect husbandry personnel from rAAV from nonhuman primates.

References: Human Gene Therapy 7: 2225-2233, 1996.

J Neuroscience Methods 71: 125-32, 1997.

Nature Genetics 3: 187-9, 1993.

NIH Guidelines for Research Involving Recombinant DNA Molecules, NIH, 1997.

Biosafety in Microbiological and Biomedical Laboratories, 3rd edition, CDC-NIH, 1993, pp. 47-52.

Human Research Report 14(7): 7-8, 1999.