A small study presented at a meeting of the American Heart Association showed that the vaccine reduced blood pressure in people with mild to moderate hypertension.
In the study, 65 men and seven women with high blood pressure were injected with either a lower or higher dose of the vaccine or with a placebo. Average age was 51.
Those who got the vaccine mounted a strong antibody response against the hormone.
The patients who received the higher vaccine dose experienced significantly lower blood pressure -- with daytime systolic blood pressure (the top number of a blood pressure reading) dropping by 5.6 millimeters of mercury (mm Hg) and their diastolic blood pressure (the bottom number of a blood pressure reading, measuring pressure as the heart rests between beats) by 2.8 mm Hg.