THURSDAY, Feb. 7 (HealthDay News) -- Tattooing is a more effective method for delivering DNA vaccines than intramuscular injection, a new German study finds.
Publishing in the online journal Genetic Vaccines and Therapy, researchers at the German Cancer Research Center in Heidelberg used a coat protein from the human papillomavirus (HPV), which causes cervical cancer, as a model DNA vaccine antigen. DNA vaccines are created using a modified form of an infectious organism's DNA.
In tests on mice, the researchers compared tattooing and intramuscular injection, with and without the adjuvants that are often given to boost immune response.
The tattoo method produced stronger antibody and cellular response than intramuscular injection, even when adjuvants were included in the injections. Three doses of DNA vaccine given by tattoo produced at least 16 times higher antibody levels than three intramuscular injections with adjuvant, the study found.
While adjuvants boosted the effect of intramuscular injection, it did not enhance the effect of tattooing.
The researchers explained that tattooing, which is done with a solid vibrating needle, causes a wound and sufficient inflammation to "prime" the immune system. It also covers a larger area of the skin than an injection, which means the DNA vaccine can enter more cells. This may be why tattooing produces a stronger immune response.
Because tattooing is painful, it may not be suitable for everyone. But it could prove useful in a number of areas, including cattle vaccination or therapeutic (rather than preventive) vaccination of humans, the researchers said.
"Vaccination with naked DNA has been hampered by its low efficiency. Delivery of DNA via tattooing could be a way for a more widespread commercial application of DNA vaccines," researcher Martin Muller said in a prepared statement.
The U.S. National Institute of Allergy and Infectious Diseases has more about vaccines.
SOURCE: BioMed Central, news release, Feb. 6, 2008