polio unmulan ke liye Vigyapan taiyar kijiye
Answers
Two polio vaccines are used to combat polyolithiasis (or polio) all over the world. The first one developed by jonas Salk and was first tested in 1952. On April 1955, Salk announced to the world that it was the injection dose of dead poliovirus. An oral vaccine was developed by Albert sabin using the attenuated polio virus. The human examination of the sabin's ticking was conducted in 1957 and licensed in 1962. Since ordinarily non - aligned persons do not have a long - term carrier condition of the polio virus and, poliovirus has no non - residential storage in nature and it is difficult for the environment to survive for an extended period of time. Thus, vaccination is an important step of eradicate the global polio transmission of the virus from person to person. Polio has been eradicated from most countries in the world and the world polio case is estimated to have been reduced from 350,000 to 1,652 in 1988.