By Matt McGrath
BBC News 

Scientists in Germany say that tattoos could be the ideal way of delivering vaccines into the body.

he researchers say that in tests undertaken with mice, tattoos were much more effective in provoking a response from the immune system.

Tattoos could be a useful way of delivering therapeutic vaccines in humans, including for some cancers.

Such vaccines have often failed to produce the expected immune response when delivered using an injection.

Vibrating needle

Tattoos have played a part in human culture for thousands of years.

Just over 100 years ago, the practice became more widely available with the invention of the electric tattoo machine in the United States. The same basic instrument is still in use to create tattoos today.

Now researchers in Germany say that the rapidly vibrating tattoo needle could be a useful way of delivering vaccines under the skin instead of insoluble ink.

In studies with mice, tattooing a vaccine produced 16 times more antibodies than a simple injection into muscle tissue.

The level of antibodies indicates the strength of the immune system's response.

Dr Martin Mueller, one of the researchers behind this work, says that the greater damage to the body caused by the tattoo needle may explain the better immune response.

The scientists say that the tattoo needles would never be suitable for preventative vaccines, such as measles, in children as the pain would be too great.

But there may well be a role for the technique in the routine vaccination of animals.