I read in the news that tests of an Alzheimer vaccine have been stopped after 4 French participants devloped encephalitis during the second, large-scale test. The vaccine has proven effective in animal test and cleared the first, limited scale test on humans. It would have been ready in ca 8 years if not for these incidents.
Not to make slight of safety concerns, but how about giving the populace a choice? A 1 in 1000 risk of encephalitis, against a 1 in 3 chance of losing your skills, your memories, your dignity and your identity slowly while still alive? I think it is a pretty good trade, but then again I'm not a lawyer.