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http://www.el-nacional.com/noticia/20476/24/Hallan-como-las-bacterias-evaden-las-vacunas.html
Spanish-English translation
Find how bacteria evade vaccines
31-Jan 11:16 a.m. | BBC
Scientists discover why some bacteria such as pneumonia, can "dress up" to evade vaccines and cause them to fail
Vaccine | Reuters
Some types of bacteria , such as from pneumonia, can evade vaccines "dressing up" , so many immunizations fail , reveals new research.
The study, published in Nature Genetics , he followed the way the pneumococcal bacteria , Streptococcus pneumoniae ( which causes potentially lethal childhood infections such as pneumonia and meningitis ) responded to the introduction of a vaccine in the United States in 2000. It is estimated that pneumococcal infections kill about one million children under five in the world each year. The success of vaccination programs , mainly in developed countries has caused a drastic reduction in the number of cases. However, scientists have observed that some of the vaccines have become less successful over time . Now, for example, is used as a new version of the pneumococcal vaccine. This vaccine works by recognizing the bacteria by coating-or capsule-a material composed of polysaccharides. What makes the immunization is to "train" immune system to attack the source of infection. There are more than 90 different types of this bacterium and each uses a different capsule. Exchange capsule pneumococcal vaccine introduced in 2000 in the United States was designed to target seven of the 90 types of bacteria. For 2007, the researchers say, cases of infection were rapidly reduced. Until this year was a sustained drop of 76% in the number of cases of septicemia, pneumonia and meningitis in children under five years. However, some strains of the bacteria continued to cause disease. Now the team of scientists from the University of Oxford, England and the Centers for Disease Control and Prevention (CDC) in the U.S. , found that the bacterium was able to change their polysaccharide capsule to escape from the vaccine. The bacteria, scientists say, changed the region of the genome responsible to produce the polysaccharide capsule of a type of bacteria that was not being attacked by the vaccine, a process called exchange capsule. This effectively managed to create a costume and became invisible to the immunization. "Imagine that each strain pneumococcal bacteria is a classroom with children using the school uniform, "said Dr. Rory Bowden, who led the study. "If a child steals something from the store on the corner a policeman in this case is vaccine- can easily identify the school that belongs looking at his uniform. " "But if the child changes his sweater with a friend from another school, the police may no longer recognize it and the child can escape." "That's how pneumococcus bacteria evade detection of the vaccine, "adds the scientist. When the researchers analyzed DNA portions of pneumococcal bacteria that had died, identified five cases of exchange of capsules. The scientists noted that one of the new strains, called P1, "quickly achieved established and spread from east to west in America. " "It became one of the most prevalent strains of 2007" added. The new vaccine is now used updated protects against 13 types of bacteria. As the BBC explains Dr. Bowden, "there are many vaccines that are used and appear stable, and continue to operate because they attack bacteria or virus that does not change." The "Holy Grail" of medicine, he says, would be able to get a universal vaccine that can attack a point that is common in all types of pneumococcus. As said Dr. Bernard Beall, CDC, "the current vaccine strategy to attack the predominant serotype of pneumococcus is extremely effective." "However, our observations indicate that the agency will continue to adapt this strategy with some measurable success. "
Spanish-English translation
Find how bacteria evade vaccines
31-Jan 11:16 a.m. | BBC
Scientists discover why some bacteria such as pneumonia, can "dress up" to evade vaccines and cause them to fail
Vaccine | Reuters
Some types of bacteria , such as from pneumonia, can evade vaccines "dressing up" , so many immunizations fail , reveals new research.
The study, published in Nature Genetics , he followed the way the pneumococcal bacteria , Streptococcus pneumoniae ( which causes potentially lethal childhood infections such as pneumonia and meningitis ) responded to the introduction of a vaccine in the United States in 2000. It is estimated that pneumococcal infections kill about one million children under five in the world each year. The success of vaccination programs , mainly in developed countries has caused a drastic reduction in the number of cases. However, scientists have observed that some of the vaccines have become less successful over time . Now, for example, is used as a new version of the pneumococcal vaccine. This vaccine works by recognizing the bacteria by coating-or capsule-a material composed of polysaccharides. What makes the immunization is to "train" immune system to attack the source of infection. There are more than 90 different types of this bacterium and each uses a different capsule. Exchange capsule pneumococcal vaccine introduced in 2000 in the United States was designed to target seven of the 90 types of bacteria. For 2007, the researchers say, cases of infection were rapidly reduced. Until this year was a sustained drop of 76% in the number of cases of septicemia, pneumonia and meningitis in children under five years. However, some strains of the bacteria continued to cause disease. Now the team of scientists from the University of Oxford, England and the Centers for Disease Control and Prevention (CDC) in the U.S. , found that the bacterium was able to change their polysaccharide capsule to escape from the vaccine. The bacteria, scientists say, changed the region of the genome responsible to produce the polysaccharide capsule of a type of bacteria that was not being attacked by the vaccine, a process called exchange capsule. This effectively managed to create a costume and became invisible to the immunization. "Imagine that each strain pneumococcal bacteria is a classroom with children using the school uniform, "said Dr. Rory Bowden, who led the study. "If a child steals something from the store on the corner a policeman in this case is vaccine- can easily identify the school that belongs looking at his uniform. " "But if the child changes his sweater with a friend from another school, the police may no longer recognize it and the child can escape." "That's how pneumococcus bacteria evade detection of the vaccine, "adds the scientist. When the researchers analyzed DNA portions of pneumococcal bacteria that had died, identified five cases of exchange of capsules. The scientists noted that one of the new strains, called P1, "quickly achieved established and spread from east to west in America. " "It became one of the most prevalent strains of 2007" added. The new vaccine is now used updated protects against 13 types of bacteria. As the BBC explains Dr. Bowden, "there are many vaccines that are used and appear stable, and continue to operate because they attack bacteria or virus that does not change." The "Holy Grail" of medicine, he says, would be able to get a universal vaccine that can attack a point that is common in all types of pneumococcus. As said Dr. Bernard Beall, CDC, "the current vaccine strategy to attack the predominant serotype of pneumococcus is extremely effective." "However, our observations indicate that the agency will continue to adapt this strategy with some measurable success. "