Vaccination against cholesterol
All content is checked by medical journalists.Vaccinating instead of swallowing pills every day - this new approach to permanently lowering high cholesterol levels has already worked in mice. An initial study with human test subjects is now underway.
High cholesterol levels play a key role in plaques being deposited in the blood vessels. Such atherosclerosis is associated with a high risk of stroke and other cardiovascular diseases. Millions of patients in Germany therefore swallow drugs such as statins, which are supposed to keep cholesterol levels in check. But they have to be taken every day - and have undesirable side effects in some patients.
Antibodies to lower cholesterol
Researchers led by Christine Landlinger from the Vienna biotech company AFFiRiS have developed an active ingredient that stimulates the immune system to form antibodies against a special enzyme. Against PCSK9. Among other things, this protein prevents the unfavorable LDH cholesterol from being removed from the blood. If it is blocked with an antibody, it can be transported away. A relatively young class of cholesterol-lowering drugs, which are available in the form of tablets, is targeting precisely this enzyme - but their effect is only very short-term and they are expensive.
Low cholesterol, healthier arteries
The newly developed vaccine, which the researchers call AT04A, is injected under the skin. To test its effectiveness, the researchers fattened mice with a genetic predisposition for arteriosclerosis with very high-fat food. In mice that had received the vaccination, the blood cholesterol level was 53 percent lower than in their unvaccinated counterparts. In addition, their blood vessels showed 64 percent fewer arteriosclerotic changes - such as deposits. Inflammation in the walls of the arteries, which is typical of atherosclerosis, was also reduced by 21 to 38 percent.
One vaccination a year
The researchers also rated the duration of the vaccination as positive: the number of antibodies in the animals' blood remained constant over the entire study period of 18 weeks. "That could mean that the antibodies are still active in humans for months after the vaccination," says Günther Staffer, chief technologist at AFFiRiS. Ideally, only an annual refreshment would then be necessary to maintain the vascular protective effect.
A phase 1 study with 72 healthy human test subjects was started at the University of Vienna in 2015 to test the safety of the active ingredient. It should be completed by the end of the year.
Eliminate unwanted immune effects
Ulrich Lauf from Saarland University also considers the approach to be very promising. In his comment published parallel to the study, however, he warns that the immunological long-term effects of the vaccination should be carefully monitored. In particular, a lowering of the cholesterol level could go hand in hand with an increased risk of diabetes. Such a connection has already been observed in patients who had taken statins or other cholesterol-lowering drugs.
