2 out of 3 wild poliovirus strains have been eradicated, says WHO

Efforts being taken to eliminate the one type found in Afghanistan and Pakistan

Babies being given polio vaccine in Agartala.

In an announcement by the World Health Organisation (WHO) on World Polio Day (October 24), an independent commission of experts declared that wild poliovirus type 3 (WPV3) has been eradicated worldwide.

This follows the eradication of smallpox and wild poliovirus type 2.

“The achievement of polio eradication will be a milestone for global health. Commitment from partners and countries, coupled with innovation, means that of the three wild polio serotypes, only type one remains,” Tedros Adhanom Ghebreyesus, Director-General of WHO and Chair of the Global Polio Eradication Initiative (GPEI) Polio Oversight Board, said on Thursday. He urged stakeholders to stay the course until final success is achieved.

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). 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.

Significant milestone

“Wild poliovirus type 3 is globally eradicated,” said Professor David Salisbury, chair of the independent Global Commission for the Certification of Poliomyelitis Eradication.

“This is a significant achievement that should reinvigorate the eradication process and provides motivation for the final step — the eradication of wild poliovirus type 1. This virus remains in circulation in just two countries, Afghanistan and Pakistan. We cannot stop our efforts now,” he added.