Vaccines are the safest, cheapest and most effective way to protect against infectious diseases. But to make a good one is still a challenge, and traditional approaches are now stretched to the limit while fatal diseases, like HIV and malaria, remain without vaccine. But a major breakthrough that turns vaccine design on its head is being published in Nature; a computational method that, from the protective antibodies of patients designs the vaccine specific to induce them (and protect against the disease).
http://skincareprogram.snack.ws/
\But not only that, showing the potential of their new method Bruno Correia from the Instituto Gulbenkian Ciência and Instituto de Tecnologia Química e Biológica (IQTB) in Portugal and colleagues from the Department of Biochemistry at the University of Washington and The Scripps Research Institute designed a
vaccine for the human-infecting respiratory syncytial virus (RSV). The vaccine was tested in rhesus monkeys (which have a very similar immune system to us), and shown to induce protective antibodies. RSV was a particular good example of the vaccine potential because not only it causes an often deadly respiratory infection among very young children so it is a dangerous virus, but is also one with which scientists have struggled to make a vaccine for a long time without success.
So how do vaccines normally work, and why there are some more difficult to make?
Nature is full of disease-inducing agents, like viruses or bacteria (collectively known as pathogens or germs) and it is easy to get infected. If we do, our immune system (the cells and organs that protect us against disease) mounts a protective response that, once the pathogen is eliminated, will leave behind a protective immune memory. This memory, if we reencounter the pathogen, can now trigger a much faster and effective attack (called secondary response) that eliminates the threat before disease develops. That is why often we only have a disease once.
Vaccines work similarly, the difference being that that first encounter is not with a live infectious pathogen, but instead with a vaccine that contains a dead, attenuated (weaken) or partial pathogen. Without giving disease these are enough, nevertheless, to create an immune memory that protects the individual if he/she ever comes in contact with the "real thing".
But despite all vaccines already developed, some serious diseases, in particular some by fast changing/mutating viruses, like HIV or hepatitis C, remain without protection. The problem is that these viruses change so fast that vaccines (and the immune memory they trigger) become obsolete very quickly. Unless that it is, if they are against those epitopes (the parts of the pathogen targeted by the immune system) crucial for viral survival, what means that they cannot be changed. This is why flu vaccines only work for one year - because the flu virus (influenza) has an extremely high mutation rate.
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