I remember Tuberculosis bacterium was completely sequenced either in 1997 or 1998 but the vaccine for T.B. is still illusive. Why is it so? When the whole genome of this bacteria is known, then why the scientist are not able to get effective target area which don’t mutate and then design the drugs to make it ineffective?
(Visit my Blog at http://salimmmn.blogspot.com/ and share your life experiences)
Re: Why Tuberculosis is still unconquered?
There is a Tuberculosis vaccine available now called the BCG vaccine. It provides immunity lasting > 15 years to 70-80% of recipients. It's given at 12 years of age in the UK if tuberculin test (the skin test for TB) is negative (i.e. all non-immune school children).
Re: Why Tuberculosis is still unconquered?
this thread should be in the social forum. because TB is not just a science problem. it is a huge social problem as well.
Infections and Inequalities is a book that really talks about the inequalities of the spread of disease. It is written by a physician, and has an anthropological/historical/humanist approach to it.
basically, there are many reasons TB isn't cured yet. a big one is that the TB bacterium is basicaly resisting the treatment. It is mutating, and the researchers have to yet find a cure for it.
another reason is that the western and developed countries got their hands on the vaccine. they had the funds to make sure that their populations got the cure. the others, didn't. the western coutnes did nothing to help them. so now, more than half the population of the world has TB. it has been wiped out from the western world, but not the rest. so now, what is going to happen is that the immigrants are going to bring a dormant form of the disease, which will spread to the general population. now they will have 2 forms of the disease with which they have to deal. i say they brought it upon themselves.
Re: Why Tuberculosis is still unconquered?
how did they bring it upon themselves..because they did not go out of their way to provide medicine to ppl of countries where teh govts had their priorities incorrect and would not spend to give shots to their ppl? how does an ordinary citizen living in the west brought it on himself?
and the statement that western countries did 'nothing' to help them is factually incorrect. if you had done any research you would have known the fuding for suh programs not only by wester countries but orgs like WHO, local governments can not be absolved of responsibility. the warlords, and generals and kings and supreme commanders and comrades could have a few less palaces and provided more medicine to their ppl but they chose not to.
Re: Why Tuberculosis is still unconquered?
a few general remarks:
-genomic sequencing of a bacterium does not mean that there will automatically be a cure/vaccine against it.
-the BCG vaccine is very old and was developed already in 1921
-the difficulty with tuberculosis is that it is very easily transmitted, it is infectious even though the person suffering from it doesn't have many symptoms, and it is becoming resistent to more and more drugs
Re: Why Tuberculosis is still unconquered?
-genomic sequencing of a bacterium does not mean that there will automatically be a cure/vaccine against it.
I know that sequencing doesn't lead to cure easily. The scientists have to identify which critical part of the genetic sequence never mutate but is vital for the organism and then what kind of protien this particular genetic sequence is generating. Only then, a drug can be designed which blocks the vital protein. But even after almost a decade no progress is visible in this direction.
Even though human genome was sequenced recently, it would take at least 100 years to know which genes produce which protiens. There are almost 30 thousand genes in our DNA.
Re: Why Tuberculosis is still unconquered?
Well, it is surprising you say that researchers will ‘design’ a drug based on their knowledge of the protein, because most drugs don’t get ‘designed’ that way, but are usually stumbled upon by coincidence. As a matter of fact, I can’t think of any drug that was specifically designed against some disease (the only one that comes remotely close to being designed is clisplatin (i’m not sure if it is this one or another) and one or two other chemotherapeutics. But even those are usually found coincidentally, and then are just modified slightly.
In contrast, the most important drugs of the 20th century, penicillin and prednison, were both discovered coincidentally.
Re: Why Tuberculosis is still unconquered?
Well, I am an Electrical Engineer and so obviously have knowledge gap with respect to medicine. But with my little knowledge, I thought that if three dimentional structure of the PROTEIN was known then perhaps a drug could be designed which perfectly locked into it and made the PROTEIN ineffective. But if it's not so then my logic says that future scientists might be able to use such knowledge to design an effective drug.
Thanks for your information.