When a vaccine for HIV is finally found, the adjuvant that makes it possible will be lucky to get mentioned in a line at the bottom of the story.

A decade ago, interest in vaccines languished as liability issues drove most companies out of the business. But the resolution of those issues, the advent of AIDS and the return of tuberculosis have stimulated renewed interest in vaccines. And the development of recombinant technology and subunit vaccines, which do not by themselves stimulate a sufficient immune response, has sparked a new interest in adjuvants.

An adjuvant can be any substance that provokes the body to mount an immune response. Yet despite the importance of adjuvants in generating an immune response to an antigen, companies with major adjuvant programs have been poorly understood by Wall Street and there are no pure play adjuvant companies. Only three companies have widely known adjuvant programs: Cambridge Biotech Corp. (CBCX), CytRx Corp. (CYTR) and Ribi ImmunoChem Research Inc. (RIBI).

'Lost in the product'

"People don't get excited about an adjuvant because it's lost in the product," said Patrick Leonard, president and CEO of CBCX. "Recombinant technology has a lot more sizzle and Wall Street understands it better. But adjuvants and recombinants have opened up an opportunity to develop products that weren't possible 10 or 15 years ago."