Vaccine Lowers Blood Pressure
Shots Hold Promise for Freeing People From Lifetime of Daily Pills
Nov. 6, 2007 (Orlando, Fla.) -- An experimental vaccine may someday free people with high blood pressure from having to swallow their medication every day.
In a new study, systolic blood pressure (the top number) fell 6 points in volunteers injected with the vaccine. Diastolic blood pressure (the bottom number) dropped 3 points.
The vaccine also unexpectedly blunted the surge in blood pressure that typically occurs between 5 a.m. and 8 a.m, says Juerg Nussberger, MD, a professor of medicine at University Hospital of the Canton of Vaud in Lausanne, Switzerland.
That's important because most heart attacks and strokes occur in the morning, he tells WebMD.
The findings were presented at the annual meeting of the American Heart Association (AHA).
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Blood Pressure Vaccine Could Improve Compliance
AHA President Daniel Jones, MD, of the University of Mississippi Medical Center in Jackson, tells WebMD that the vaccine shows promise for improving control of blood pressure.
Nearly one in three American adults has high blood pressure, which increases the risk of stroke, heart disease, heart failure, and kidney failure.
But in the U.S., only 37% of people with high blood pressure have it under control, mainly due to a failure to take their medication as directed, he says.
"That's what makes this such an intriguing approach. The hope is that you could give a few doses ... and then you wouldn't have some of the compliance issues related to taking medications on a daily basis," Jones says.
Nussberger says that if the vaccine pans out in future trials, people would only have to come in for a shot every four months.
Blood Pressure Vaccine Works on Same Target as Drugs
The vaccine causes the body to produce antibodies that target angiotensin II, a chemical in the body that constricts blood vessels and raises blood pressure. Blood pressure medications known as angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers also target angiotensin II.
The study involved 72 patients with mild to moderate high blood pressure who were injected with either a lower dose of the vaccine, a higher dose, or a placebo, with boosters four and 12 weeks later.
Only the higher dose significantly lowered blood pressure, compared with placebo.
There were no serious side effects with either dose, but all the participants suffered mild reactions such as pain or swelling in the area where the vaccine was injected.
The next step: Another small trial to determine whether a different injection regimen will safely reduce blood pressure further.
Cytos Biotechnology, which makes the vaccine, funded the trial.