PEOPLE have pampered, plucked and styled their hair for the sake of vanity
for centuries. Now it could be put to a more noble purpose鈥攁s a cheap and
painless way to administer vaccines.
About seven years ago, scientists discovered that injecting purified genes
from a virus could immunise animals against the live virus. This trick works
because the DNA produces viral proteins, which spur the immune system into
action. One attraction of this approach is that DNA vaccines are far cheaper to
produce than conventional ones.
Paul Khavari of Stanford University was looking for a way to get DNA into the
body without needles. He rubbed DNA on the skin of mice as a negative control
for other techniques, thinking it would not work. But as Khavari and his
colleagues report in Nature Biotechnology (vol 17, p 870), the DNA
entered cells and primed the rodents鈥� immune system to react to the viral
protein it coded for. 鈥淚t was a bizarre thing we couldn鈥檛 explain and we didn鈥檛
believe,鈥� says Khavari.
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It turned out that the DNA was getting in through hair follicles. Mice that
lacked follicles did not take up the DNA. However, while mouse and human skin
are similar, it remains to be seen if human follicles can also act as DNA
gateways.
Jonathan Vogel, a skin specialist at the National Cancer Institute near
Washington DC, calls the approach promising. 鈥淚magine a vaccine you can deliver
on a patch,鈥� he says. 鈥淧eople who don鈥檛 like needles would like that.鈥�