Someday a series of shots may replace those pesky blood pressure pills that millions of Americans take each day, new research suggests.

A vaccine, known as CYT006-AngQb, has shown some promise in a recent trial, according to Swiss researchers who reported the study during at the American Heart Association annual meeting in Orlando this week. The vaccine works by inhibiting angiotensin II, a molecule that constricts blood vessels and raises blood pressure

Study subjects experienced a drop in their systolic blood pressure (the top number in a reading) and diastolic blood pressure (the bottom number) after just the injection. In addition, the vaccine appeared to reduce the typical blood pressure surge that occurs between 5 a.m. and 8 a.m., according to the study report. A vaccine could help to eliminate the compliance problems associated with daily pills.