Q.1. Why did early attempts at the development of polio vaccine fail ?
Answers
In April 1955 more than 200 000 children in five Western and mid-Western USA states received a polio vaccine in which the process of inactivating the live virus proved to be defective. Within days there were reports of paralysis and within a month the first mass vaccination programme against polio had to be abandoned. Subsequent investigations revealed that the vaccine, manufactured by the California-based family firm of Cutter Laboratories, had caused 40 000 cases of polio, leaving 200 children with varying degrees of paralysis and killing 10.
Paul Offit, paediatrician and prominent advocate of vaccination, sets the `Cutter incident' in the context of the struggle of medical science against polio and other infectious diseases over the course of the 20th century. He reminds us that, within a decade of Karl Landsteiner's identification of the polio virus in 1908, an epidemic in New York killed 2400 people (mostly children) and left thousands more with a life-long disability. In the 1950s, summer outbreaks in the USA caused tens of thousands of cases, leaving hundreds paralysed or dead. `Second only to the atomic bomb', polio was `the thing that Americans feared the most'.
Answer:
the oral vaccine(OPV)was recommended to use in the United states for almost 40 years,from 1963 until 2000.the results have been miraculous:polio was eliminated from the United States in 1979 from the western hemisphere in 1991.
since 2000,only IPV is recommended to prevent polio in the United States.
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