New monovalent oral polio vaccines mOPV become available to enhance the impact of supplementary immunization activities. Four endemic countries remain: Afghanistan, India, Nigeria and Pakistan. Outbreaks in Yemen and Indonesia—which suffer the largest, single-country outbreaks in recent years —are successfully stopped. More than million children are immunized in 27 countries. On International Peace Day, 80 previously inaccessible children are reached with polio vaccine in southern Afghanistan.
A new outbreak of polio spreads from Nigeria to West Africa. Large outbreaks with more than cases wild poliovirus occur in both Tajikistan and Congo. Transmission is stopped by the end of the year in both countries. The globally synchronised switch from trivalent to bivalent oral poliovirus vaccine is implemented in April This is the first part of the phased withdrawal of all oral polio vaccine.
It took somewhat longer for polio to be recognized as a major problem in developing countries. Lameness surveys during the s revealed that the disease was also prevalent in developing countries.
As a result, during the s routine immunization was introduced worldwide as part of national immunization programmes, helping to control the disease in many developing countries. When the GPEI started, polio paralysed more than children worldwide every day. Since then, more than 2. There has also been success in eradicating certain strains of the virus; of the three types of wild polioviruses WPVs , the last case of type 2 was reported in and its eradication was declared in September ; the most recent case of type 3 dates to November and this strain was declared as globally eradicated in October Who we are Our Mission.
History of Polio. It hit without warning. It killed some victims and marked others for life, leaving behind vivid reminders for all to see: wheelchairs, crutches, leg braces and deformed limbs.
In , it paralyzed year-old Franklin Delano Roosevelt, robust and athletic, with a long pedigree and a cherished family name. If a man like Roosevelt could be stricken, then no one was immune. Each June in America, like clockwork, came newspaper photos of jam-packed polio wards and eerily deserted beaches. Newspapers ran tallies of the victims—age, sex, type of paralysis—akin to baseball box scores. Parents checked for every known symptom: a sore throat, a fever, the chills, nausea, an aching limb.
Did the toes wiggle? Could the chin reach the chest? In truth, polio was never the raging epidemic portrayed by the media, not even at its height in the late s and early s. Ten times as many children would be killed in accidents in these years, and three times as many would die of cancer. What had changed following World War II was the incidence of polio in the United States as well as the rising age of the victims, a quarter of whom were now older than From to , reported polio cases doubled to eight per ,, doubled again to 16 per , between and , and climbed to 25 per , from to , before peaking at 37 per , in The drive to combat polio was led by the National Foundation for Infantile Paralysis, now known as the March of Dimes.
The genius of this foundation lay in its ability to single out polio for special attention, making it seem more ominous, and curable, than other diseases. Its strategy would revolutionize the way charities raised money and penetrated the world of medical research.
Millions of foundation dollars would be spent to set up virology programs and polio units across the country, with the first grant going to the Yale School of Medicine in Although research funding went in many directions, one point became increasingly clear: the best way to prevent polio would come through a vaccine. This was hardly a revelation. Vaccines already had proved successful against other viruses—smallpox and rabies being notable examples.
But producing a safe and effective one against polio would not be easy. Three major problems had to be solved. First, researchers would have to determine how many different types of poliovirus there were. Second, they would have to develop a safe and steady supply of each virus type for use in a vaccine. Third, they would have to discover the true pathogenesis of polio—its route to the central nervous system—in order to fix the exact time and place for the vaccine to do its work.
The first problem took the longest to solve. Dozens of strains were examined, using the stools, throat cultures and, in fatal cases, nerve tissue of polio victims. Most of this work was done by ambitious young researchers hoping to attract March of Dimes grant money. The list included Salk at the University of Pittsburgh. As it turned out, all of the tested strains of poliovirus fit neatly into three distinct types. The poliovirus family proved remarkably, conveniently, small.
A polio vaccine, then, would have to protect against all three virus types to be successful. The next step involved the harvesting of poliovirus that was safe enough, and plentiful enough, for use in that vaccine. At Harvard, John F. Enders, Ph.
Robbins, M. Weller, M. By cultivating these viruses in a test tube, rather than in the brain or spinal column of a monkey, researchers could get a better look at the changes occurring in polio-infected cells. Thanks to the polio vaccine, dedicated health care professionals, and parents who vaccinate their children on schedule, polio has been eliminated in this country for more than 30 years.
This means that there is no year-round transmission of poliovirus in the United States. It takes only one traveler with polio to bring the disease into the United States. People most at risk are:. The best way to keep the United States polio-free is to maintain high immunity protection against polio in the population through vaccination.
Skip directly to site content Skip directly to page options Skip directly to A-Z link. Global Immunization. Section Navigation. Facebook Twitter LinkedIn Syndicate. Polio Elimination in the United States.
Minus Related Pages. Polio Once Caused Widespread Panic. Close Introduction of the polio vaccine dropped polio paralysis cases in the U.
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