A Vaccine for High Blood Pressure?

Angiotensin II is the villain in high blood pressure, or hypertension, and there are several successful drugs that work by neutralizing it – the angiotensin receptor blockers (ARBs) and the angiotensin-converter inhibitors (ACE-inhibitors). A new idea, however, is a vaccine that’s a virus-like particle conjugate that targets Angiotensin II – it’s administration produces antibodies to angiotensin II that have a half-life of 4 months, so it wouldn’t have to be given very often. .

In a study reported in the Lancet, European researchers randomly allocated 72 patients with mild-to-moderate high blood pressure to take one of two doses of vaccine (100 or 300 micrograms) or a placebo. Injections were given at weeks 0, 4, and 12.
By week 14, one in 5 of the vaccine recipients had experienced brief flu-like symptoms, and all had developed antibodies against angiotensin II. Those who had the 300-microgram dose had significant drops in blood pressure compared with the placebo recipients, especially in the early morning (-25 mm Hg systolic, -13 mm Hg diastolic).
Enthusiasm for these impressive results was dampened a bit by experts, who worried about the risks of a treatment when the effects are not rapidly reversible. But we know that many hypertensive patients don’t take their blood pressure meds, for one reason or another. An injection every 3-4 months may be easier to tolerate than the effects of non-compliance with prescribed pills.

Comments

[Judith]

Angiotensin II is not really a villain. Blocking it is useful for lowering blood pressure, since blood vessels will relax when Ang II is blocked and so the wider diamenter of the blood vessels causes a drop in blood pressure. If you don't have elevated blood pressure Ang II function is not bad. For an explanation of the renin-angiotensin system and the drugs used to modulate it see http://www.infobloodpressure.com/drugs/renin_angiotensin.html