Some 70 million American adults have high blood pressure. Three quarters of them rely on medication to keep the condition in check. But you've got to remember to actually take the daily dose. Now researchers have devised a longer-lasting alternative: a vaccine to lower blood pressure - for rats, at least. Scientists jabbed hypertensive rats with three doses of the formulation. It's a DNA vaccine—containing DNA fragments from angiotensin II—a hormone that boosts blood pressure, as well as fragments from hepatitis B, to guarantee the immune system’s attention. Cells suck up the vaccine's DNA, and start pumping out the proteins the DNA codes for. When the host defenses gets a whiff of the proteins, it reacts. It really revs up against the hepatitis B fragments. And while it’s at it, it starts taking out some angiotensin II as well. The result is a reduction in angiotensin II's usual blood pressure raising effects—similar to what blood pressure meds like Benicar do. Less angiotensin II means more relaxed blood vessels, and a drop in pressure. That effect lasted six months in the vaccinated rats, and lengthened their lifespan by eight weeks. Necropsies on the vaccinated rats revealed healthier heart tissue than normally found with high blood pressure, and no damage to their kidneys or livers. The results are in the journal Hypertension.