Is Alzheimer’s Infectious, and Is a Vaccine Possible?
Meryl Comer: For the general public the other issue is, is Alzheimer’s infectious? What would...
Dr. Arancio: My take on it is that it might be, but wait a second. It’s not that I'm thinking it’s like a flu and you might get infected. However, we were talking before at tau protein. There is common work and showing that actually it could spread within the brain just like prion disease, the same way, so it starts from one area and then it spreads all over the brain, so it’s not infection in the sense that we understand normal get infected, but it could once it is initiated in a certain part of the brain there is the possibility. It’s not 100% sure, but there are people now we’re starting to see that there is this spreading within the brain, because this tau protein comes out of the cells and spreads to the next cells and then from one area and goes all over the brain and so the disease it’s classical normal... these plaques. They start from a part of the brain and what we call the temporal lobe an then goes from the lobe. At very end it just goes to the occipital lobe, which is where we see, so from this point of view there could, although it has not been totally demonstrated, but there are some people that are following along this path.
Meryl Comer: Dr. Gandy?
Dr. Gandy: I think for classical thoughts about infections I mean like epidemics of flu I would not put Alzheimer’s disease in that category. Back in the 80s a neurologist and scientist and NIH, Carlton Gatacheck and colleague Joe Gibbs tried very, very hard to transmit extracts... use extracts from human Alzheimer’s disease to give the disease to monkeys and they never ever saw any evidence that could be the case.
Meryl Comer: To Dr. Arancio. Dr. Arancio, is a vaccination possible?
Dr. Arancio: All the attempts that are done so far have failed, which does not mean that they will not work in the future. Indeed a very good amount of research in terms of treatment research done on this, on finding a vaccine. Then one thing that we should also know is that there are two kinds of vaccines. One kind of vaccine is what we call "active vaccination," which would be just the same thing that we do with the flu, so you take vaccine and you’re protected for a certain number of years in your life... of your life. In this case one would think about prevention of using vaccine to prevent the disease. There is also what they call passive vaccinations, which will be more short time [...] vaccine. Instead of giving, trying to prompt the body to make what you call the antibodies against the for instance beta amyloid, we give just the antibody that they have a short life. We have to say though that so far all the attempts to fix the problem have failed, but like all the others anyway. That’s what we’re facing, but it could be... it is for sure an interesting avenue to pursue. It would be great if at that time of birth or very short afterward if there were a vaccine, an active vaccination and that will protect us at the very end, but we have to be very careful there too because if for instance what do we vaccinate against? If we vaccinate against A-beta, which is this beta amyloid and if it has some normal function through our life it then could be a negative. We could get also negative effect.
Meryl Comer: For those who know the ravages or have watched the ravages of Alzheimer’s disease in a family, the notion that it might be reversible... Dr. Guarente?
Dr. Guarente: Is it possible?
Meryl Comer: Is it possible?
Dr. Guarente: Well I do get asked that question a lot more broadly about aging: "Is it possible?" And my belief in general is to think that almost anything is possible okay, where science is concerned. Now I do think that at the moment all the research effort is focused on slowing down Alzheimer’s, slowing down aging, slowing down the buildup of and the progression of what is happening in the brain and I think that is the way it has to start because I think we have to be able to do that as a prelude to doing anything more. Now if we can get to effective drugs that can slow the progression of Alzheimer’s and maybe even arrest the deterioration, then I think ultimately, yes, it’s possible. You can imagine replacing neurons that have died by stimulating division of stem cell, neuronal stem cells, and things of that sort, so I think, yes, it’s possible, but I think the way I organize my thoughts on this is first we have to think about the disease and how do we stop it. How do we stop the buildup of damage and how do we arrest it and then we can really... that might give us the space to think about can we actually reverse it and I would give the same kind of answer about aging.