Cholesterol-Lowering Vaccine May Help Prevent Heart Attacks
At least one person in the United States suffers from a heart attack every 43 seconds, but this prevalence may someday change with a vaccine that can lower a person's cholesterol levels.
Human Trial Underway
Researchers have started a clinical trial to test the vaccine after studies involving mice were successful. If the vaccine is found to be effective in humans, it may provide a long-lasting and even convenient treatment for individuals with high levels of cholesterol known to cause potentially deadly heart diseases and stroke.
The vaccine designed to help prevent heart disease is now being tested on 72 volunteers. The human trials aim to test the safety of the experimental treatment that stops fatty deposits from clogging the arteries, which contributes to progression of heart diseases.
The vaccine works by helping the body's immune system produce antibodies that attack the protein PCSK9 that allows the bad cholesterol low density lipoprotein (LDL) to build up in the bloodstream.
The jab, which is injected under the skin, would give patients an alternative to taking pills every day to cut their risk of angina, stroke, and heart attacks.
Findings In Studies Involving Mice
In experiments involving mice that had been fed high-fat and Western-diet to induce high levels of cholesterol, the treatment reduced LDL cholesterol by up to 50 percent over 12 months.
It also appears to provide protection against the buildup of fatty deposits in the arteries. The condition known as atherosclerosis, can eventually lead to the development of heart disease and other complications.
In mice, the animals that were vaccinated had 53 percent lower total cholesterol, 64 percent less narrowing of the arteries and up to 28 percent lower levels of some markers of blood vessel inflammation compared with the animals that did not get the vaccine.
"AT04A vaccine induces an effective immune response against PCSK9 in APOE*3Leiden.CETP mice, leading to a significant reduction of plasma lipids, systemic and vascular inflammation, and atherosclerotic lesions in the aorta," the researchers reported in a study published in the European Heart Journal on June 19.
The research also showed that the antibodies continued to work throughout the study period and the concentrations of these antibodies remain high even at the end of the study, suggesting that the treatment would continue to reduce cholesterol levels for some time, which could result in long-lasting effect.
Downside Of Current Treatments
Although there are currently available treatments for lowering cholesterol levels, the researchers pointed out that these medications need to be taken on a daily basis and sometimes even cause harmful side effects. The animal studies suggest that the effect of the new vaccine can last long-term.
"If these findings translate successfully into humans, this could mean that, as the induced antibodies persist for months after a vaccination, we could develop a long-lasting therapy that, after the first vaccination, just needs an annual booster," said study researcher Gunther Staffler, from AFFiRis, the company that developed the vaccine. "This would result in an effective and more convenient treatment for patients, as well as higher patient compliance."