Tuesday, April 20, 1999 Published at 10:34 GMT 11:34 UK
Heart disease vaccine trial
Clogged arteries can lead to heart attacks
Researchers are about to start human trials of a vaccine to prevent heart disease.
The drug has shown promising results in animal tests.
Researchers say it boosts the body's natural ability to cope with cholesterol, but one GP has warned that a vaccine could leave the body open to other forms of disease.
The researchers at Avant Immunotherapeutics said their vaccine raised levels of high-density lipoprotein - HDL or "good" cholesterol - by 35% in rabbits.
It also reduced the number of plaques - which clog up arteries - by 40%.
Boosting the body's immune system
Dr Una Ryan is president and chief executive officer of company, based in Needham, Massachusetts.
"This is self-help, your own body, your own immune system, doing the work for you.
"What we're doing here is giving a little part of a molecule that's in everybody and teaching the immune system to react against it and lower the levels."
She said the company had high hopes for the human trials, which will take place in the US.
"We are very pleased with these results, which clearly demonstrate the feasibility of our vaccine approach as a novel strategy for preventing or treating atherosclerosis," she said.
"As a result, we are preparing to initiate human clinical safety studies with the vaccine this summer."
Atherosclerosis is an abnormal thickening and loss of elasticity of the walls of the arteries.
Vaccine could create vulnerability
However, Dr Peter Mansfield - a GP opposed to vaccines - said any such vaccine would only make the body lazy.
"Heart disease is not the only issue here - most of our problems as they are emerging have to do with general immunity.
Dr Mansfield said the vaccine was only being developed because a company could see how to make a profit out of it.
This was a general problem in modern medicine, he said.
Antibodies target protein
Dr Lawrence Thomas, of Avant, explained how the vaccine works to the Federation of American Societies for Experimental Biology in Washington.
He said the vaccine produces antibodies that block the activity of cholesteryl ester transfer protein (CETP).
CETP is responsible for HDL being converted into low density lipoprotein - LDL or "bad" cholesterol.
While HDL is carried away from arteries, LDL is left in the arteries to cause blockages.
High levels of LDL are a big risk factor for atherosclerosis and heart disease.