Yes. At least that is the case for vaccines against Alzheimer's disease. There have not been any successes in the past few years, in spite of the large amount of research that is being done in this field. Since the 1990s and the beginning of the last decade there has of course been research on vaccines against Alzheimer's. A great deal has been learned, but no effective medications have been developed that would be approved by the FDA or Health Canada. There is still work to be done.
On November 30th, 2010. See this statement in context.