Hypertension Vaccine in the Works
High Blood Pressure Vaccine Shows Promise in Preliminary Test
March 7, 2008 -- A vaccine for high blood pressure is in the works.
The experimental vaccine doesn't have a brand name yet. It's designed to
help treat -- not prevent -- high
blood pressure (hypertension).
In a preliminary study, the high blood pressure vaccine curbed early morning
blood pressure in patients with mild-to-moderate hypertension.
The vaccine spurs the body to make antibodies that target a protein called
angiotensin II, which helps constrict blood vessels. By sidelining angiotensin
II, blood vessels stay more relaxed, keeping blood pressure lower.
There are drugs that act
on angiotensin II. But some high blood pressure patients don't take their
medicines as instructed, hence the interest in a blood pressure vaccine.
The preliminary study focused, first and foremost, on the vaccine's
The study included 72 adults with mild-to-moderate hypertension. Over three
months, they got either three injections of a high dose of the vaccine, three
injections of a low dose of the vaccine, or three injections of a placebo.
The patients got their first shot when the study started, a second dose a
month later, and the third dose three months after the study began. They also
got their blood pressure monitored around the clock at the study's start and
again two weeks after their last shot.
No serious side effects were linked to the vaccine. Adverse events were
generally mild and included injection site reactions and flu-like symptoms.
Further Studies Needed
The study wasn't designed to test the vaccine's effectiveness. But the
results show a drop in early morning blood pressure with the higher dose of the
Longer, larger studies are needed to further test the vaccine.
If the vaccine fares well in those tests, patients would need "a few
injections per year," write the researchers, who included Alain Tissot,
PhD, of Cytos Biotechnology AG, the Swiss company that makes the vaccine and
funded the study.
An editorial published with the study in The Lancet cautions that the
study was "small and exploratory" and that further safety and
effectiveness tests are needed.
"Nevertheless, the results of this new biotherapy for hypertension are
intriguing and promising, and vaccination for hypertension may turn out to be
very useful in many patients," write the editorialists, who included Ola
Samuelsson, MD, of Sahlgrenska University Hospital in Goteborg, Sweden.