Wild Poliovirus type 3


  • Recently the World Health Organisation on World Polio Day (October 24), declared that wild poliovirus type 3 (WPV3) has been eradicated worldwide. This follows the eradication of smallpox and wild poliovirus type 2. With this, 2 out of 3 wild poliovirus strains have been eradicated.

About Polio:

  • Polio (poliomyelitis) is a highly infectious disease caused by a virus. The virus is transmitted by person-to-person spread mainly through the faecal-oral route. It Polio mainly affects children under 5 years of age.
  • It invades the nervous system, and can cause total paralysis in a matter of hours. 1 in 200 infections leads to irreversible paralysis. Among those paralysed, 5% to 10% die when their breathing muscles become immobilized.
  • There is no cure for polio, it can only be prevented. Polio vaccine, given multiple times, can protect a child for life.


  • There are three individual and immunologically distinct wild poliovirus strains: wild poliovirus type 1 (WPV1), wild poliovirus type 2 (WPV2) and wild poliovirus type 3 (WPV3). Efforts are being taken to eliminate the wild poliovirus type 1. This virus remains in circulation in just two countries, Afghanistan and Pakistan.
  • Symptomatically, all three strains are identical, in that they cause irreversible paralysis or even death. But there are genetic and virological differences, which make these three strains three separate viruses that must each be eradicated individually.

Source: TH

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