Tuesday, November 29, 2011

Improved vaccine protects you a 100-fold better

Vaccines function by eliciting an immune response in the body. When it encounters an actual pathogenic micro-organism afterwards, our defences are prepared for it. This has been so effective that we succeeded in eliminating a few diseases completely, such as smallpox. Now, a team of scientists from Harvard Medical School has created a new version of the vaccine that is supposed to perform a hundred times better than conventional ones. If it proves to be effective in humans, we might be able to get rid of more life-threatening diseases.

How it works
The vaccine consists of two distinct compounds: a carbohydrate group and a protein group, which bound together form something that is called a glycoconjugate. After testing with different setups with variable protein parts, they found that the corresponding immune response remained unchanged. That lead to the conclusion that the carbohydrate group is the most important factor to elicit an immune response. This raised an eyebrow, because many scientists assume that the cells responsible for the body's response recognize protein parts. Based on their results, the researchers made a vaccine that possesses much more carbohydrate particles compared to conventional ones. This elicited the 100-fold stronger immune response that was reported in their study.
The immune response
For their experiments. the researchers from Harvard used mice, that were vaccinated with the carbohydrate-rich compound. In response to the vaccination, specialized white blood cells called T lymphocytes were activated. These cells are responsible, among others, for an attack launched against a specific foreign molecule, which is in this case the carbohydrate-rich compound. The scientists managed to find carbohydrate groups attached to T cells after they examined the mice, further illustrating proof that the white blood cells respond to the carbohydrate part of vaccines.

Other types of vaccines
Using artificially constructed vaccines with carbohydrate and protein groups is not the only way to make a vaccine. Whenever possible, scientists create them with the help of the pathogen that the vaccine is developed against. By modifying the pathogen, it is possible to weaken it and inject it in humans. Though the micro-organism is no longer able to cause disease, it will still elicit an immune response. Of course, it is of paramount importance to be absolutely sure about safety, as a dysfunctional vaccine in which the pathogen is still potent can have devastating consequences. In addition, vaccines can be developed by looking at specific proteins on the cellular surface. By making a vaccine that contains these proteins, the body will be immunized against that particular protein, but because it is attached to a pathogen, it will consequently be eliminated.

Vaccination works with the principle of memory. After the immune system encounters a pathogen for the first time, a specific attack is launched, in which only the cells that are able to recognize the right molecular patterns multiply. After the threat is eliminated, the immune cells die, but a few of them remain as specialized memory cells. When the pathogen in question invades for the second time, it is recognized much faster, and the body is able to launch an attack much more efficiently and deadly. That explains why we don't get sick from certain pathogens after we have been vaccinated.

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