"Right now there is a major push to utilize synthetic carbohydrates as antigens in order to control the purity and composition and avoid possible contamination," Seeberger explained. His own group, together with a biotech company ?Ancora Pharmaceuticals in Medford, Mass. ?is working on one such malaria vaccine that is in late-stage preclinical trials. Other candidate vaccines against anthrax and tuberculosis are at an earlier stage of development.
One major drawback with carbohydrate vaccines is the difficulty in getting them to produce a strong immune response. Vaccine manufacturers achieve this by adding a booster substance ?an adjuvant. The standard existing adjuvant, alum, has limitations. Potential alternative adjuvants are toxic, expensive or have other problems.
Seeberger’s candidate vaccine combines the delivery vehicle, immune-stimulating antigen and adjuvant into one package.
The delivery vehicle is an influenza virosome ?the empty envelope of the influenza virus. These flu virus shells contain none of the infectious genetic material in full-fledges flu viruses. The virosome also acts as an "adjuvant," boosting the immune response of the candidate vaccine. The antigen is a synthetic carbohydrate similar to substances on the surface of the leishmaniasis bacteria.
With laboratory studies showing that the candidate vaccine produces a strong protective action against leishmaniasis, Seeberger’s group is moving on to the next step toward a leishmaniasis vaccine ?tests in animals.
"To date, carbohydrates have not been used on this delivery platfo
Source:American Chemical Society