Could New Vaccine Effectively Treat Hypertension?
Japanese scientists have developed a new DNA vaccine that may lower blood pressure for up to 6 months, according to a new study in the journal Hypertension.
“This is the first report of a DNA vaccine for hypertension in animal experiments,” says study co-author Hironori Nakagami, MD, PhD, a professor at Osaka University in Japan.
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The immunization targets angiotensin II, a hormone that raises blood pressure by causing blood vessels to constrict and forces the heart to work harder. The vaccine works similarly to common ACE inhibitors, which help blood vessels relax and open up in order to lower blood pressure.
Nakagami and his colleagues immunized hypertensive rats 3 times at 2-week intervals with needleless injections. The group that received the vaccine showed several benefits, including:
• A consistent reduction in blood pressure for at least 6 months.
• Less hypertension-associated tissue damage to the heart and blood vessels.
• Significantly improved survival rates.
While other types of vaccines—such as peptide vaccines—have been tested for hypertension, they haven’t been able to produce lasting therapeutic benefits and some have caused undesirable side effects.
“Although the peptide vaccine for angiotensin II has been already reported, our system is more long-acting,” Nakagami says. “The combination of HBc (carrier protein) and angiotensin II (antigen) might be well matched for this vaccine.”
In addition, the rats that received the vaccine showed no signs of damage to other organs, such as the kidneys or liver. The team hopes to eventually develop human vaccine therapy to treat hypertension, offering a novel therapeutic option that would relieve patients of the burden of taking a pill every day.
“The advantage of this vaccine is that it could improve adherence (to treatment) because patients with hypertension sometimes forget to take their antihypertensive drug or some cannot take a drug by themselves, such as those with stroke or dementia,” Nakagami says.
The researchers also suggest that a DNA vaccine may provide a cheaper, effective antihypertensive treatment in developing countries, where antihypertensive drugs are expensive.
Nakagami and his colleagues plan to move to clinical trials of the vaccine in humans in a few years. They believe this technology can also be applied to create other vaccines.
—Colleen Mullarkey
Reference
Koriyama H, Nakagami H, Nakagami F, Osako MK, Kyutoku M, Shimamura M, et al. Long-term reduction of high blood pressure by angiotensin II DNA vaccine in spontaneously hypertensive rats. Hypertension. 2015 May 26. [Epub ahead of print].