The virus that causes polio is very infectious. People are affected differently by it; some individuals don't feel unwell at all, while others complain of everything from a sore throat to fever, vomiting or stomach discomfort to a stiff neck or headache. The virus infects the brain and spinal cord by first replicating, or reproducing, itself in the intestines and then moving via the circulation. As the poliovirus replicates and assaults the neurological system, it causes paralysis.
Since 1955, Polio Vaccines has been accessible. In 1955, the inactivated polio vaccine (IPV), administered as an injection, became widely accessible. Oral polio vaccination (OPV), which is more practical, was administered as liquid drops into the mouth. It came about in 1961. OPV was advised for use in the US from 1963 to 2000, a period of approximately 40 years. The outcomes were miraculous: polio was eradicated from the Western Hemisphere and the United States in 1991, respectively.
