Could Vaccines Someday Improve Heart Health?
In early studies, injections lowered cholesterol and blood pressure in animals
"It's a hormone that increases blood pressure, and many of the common drugs antagonize it and reduce blood pressure," said Barbara Howard, a senior scientist at MedStar Health Research Institute and a professor at Georgetown University Hospital, in Washington, D.C. "The idea is if you can knock out the production, you can have a sustained reduction that will last longer."
There are some concerns about medicines or vaccines that target this hormone, however. "It's part of a very complex network of hormones that regulate sodium balance in your body," she said. "It has to be very tightly regulated, or it can cause damage to the whole vascular system."
In this study, the vaccine reduced the rats' blood pressure for months and reduced damage to the heart and blood vessels associated with high blood pressure. It also did not cause any damage to the kidneys, heart or liver.
While these findings are promising, Howard said there needs to be more study before it is ready as a vaccine for humans.
"There's a lot of danger of overshooting and disturbing that sodium balance, and they didn't give any real data in this report," she said. "It's got to be done in humans, and it's got to be accompanied by many more measures of functional safety. If you lower it enough to affect blood pressure, can you do that without affecting sodium balance?"
At this point, the vaccine is at least five to six years away from human trials, according to study co-author Dr. Hiroshi Koriyama of Osaka University, in Japan.
There likely will be a similar amount of time needed to bring the cholesterol vaccine to human trials, said AHA spokesperson Dr. James Howard.
However, he noted that human trials now are taking place for another form of the cholesterol vaccine that has to be taken every couple of weeks by injection.
In the meantime, the AHA recommends eating a heart-healthy diet, getting weekly aerobic and muscle-strengthening activity, and avoiding tobacco smoke as good ways to help control cholesterol.
Because the studies were presented at a medical meeting, the data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.