Sydney, Oct 30 (IANS) Most vaccines need a booster, but the best ones are too toxic for human use. Now New Zealand scientists believe they have created a powerful and safe adjuvant, as a booster is technically called, and are conducting trials with it as part of a new cancer vaccine. Scientists at Industrial Research Limited (IRL) in Wellington were hopeful that the new synthetic adjuvant could work across a wide range of vaccines against viruses, bacteria and cancer.

The commercial potential is large, as only one adjuvant is currently licensed for use in human vaccines in the US, according to Richard Furneaux, group leader of carbohydrate chemistry at IRL.

For years immunologists have used Freund’s adjuvant to boost immune responses in animal studies of vaccines. It’s usually an extract from the mycobacteria that cause TB.

But the associated toxic side-effects have prevented these adjuvants being used in humans. The new adjuvant is a glycolipid, a carbohydrate-based molecule derived from the cell wall of mycobacteria.

It seems to have much of the same immune system-stimulating effect without the dangerous side-effects. And because the new adjuvant has been made from scratch it can be precisely defined, according to an IRL release.

“Modern vaccines need to be composed of chemically defined components,” explained Richard. “Our adjuvant appears to have similar properties to old-fashioned adjuvants, but it has been chemically synthesised.”

Now IRL has entered into an agreement with a leading New Zealand research centre, the Malaghan Institute of Medical Research, to test out their adjuvant with a cancer vaccine.

The vaccine uses the patient’s own cells, in this case immune system cells called dendritic cells, which have been trained to recognise tumour antigens. These trained cells turn the immune system against the tumour.