Swiss biotechnology company Cytos has caused a stir with the publication of promising data concerning its new hypertension vaccine.

Results from a Phase IIa clinical trial with the blood pressure jab CYT006-AngQb, which have been published in The Lancet, showed that 72 people immunised against the angiotensin II hormone, which is responsible for high blood pressure, only suffered very mild, flu-like, side effects. Martin Bachmann, chief scientific officer at Cytos, said that the study is the result of “basic and applied research that aims at employing our own immune system to protect us not only from infectious diseases, which is the traditional field for vaccines, but also from common chronic diseases like hypertension”. He added that the positive outcome of this study “is therefore an important milestone.”

The response to the Lancet study has caused considerable excitement in the media, given that high blood pressure affects a quarter of all adults and doubles the risk of dying from heart disease or stroke. Current treatments Most patients currently take a daily combination of treatments such as ACE inhibitors, angiotensin receptor blockers, calcium channel blockers and diuretics, but the side effects can be quite severe, leading to fatigue, nausea, diarrhoea and impotence.

However the biggest problem concerning the existing drugs is compliance and an immunisation programme could theoretically save thousands of lives and millions of dollars. Nevertheless, Cytos and other groups have warned against getting too excited over the data.

Jeremy Pearson, associate medical director at the British Heart Foundation, said the results show that immunising people against angiotensin II may be a promising way to tackle high blood pressure but “the study was a small one designed to test treatment safety rather than long term results”. These will need to be backed up by “bigger, longer-term trials before we know whether it can offer real hope to high blood pressure sufferers”.

He added that immunisation may be of particular benefit “to people who find it difficult to stick to high blood pressure medication or suffer side effects, but there is still a long way to go before this approach replaces the highly effective current treatments”.