ISLAMABAD, July 29: A rare and dangerous strain of a mutated polio virus has reappeared in Pakistan to the dread of the long-time polio-free world.

Dr Alias Durray, chief of the World Health Organisation’s polio eradication programme in Pakistan, confirmed to Dawn that the strain, which has close genetic similarities with the globally eradicated P2 strain, has paralysed a baby boy in Mastung district of Balochistan.

This latest case has followed the one reported from Jafarabad district of the province in May this year. Mastung and Jafarabad district are 300 kilometres apart.

The polio virus has three types of strains termed P1, P2 or P3 strain. Immunity from any one strain does not protect a person from the other strains. The P2 virus had been eradicated globally in 1998, and only the P1 and P3 strains remain.

What is sad is that a strain similar to the mutated polio virus had been stopped after it first broke out and struck 15 children in Qila Abdullah area of Balochistan in 2011.

“This outbreak was successfully stopped with a series of campaigns,” recalled the WHO official.

“From then on, the virus was sporadically detected in Jafarabad (one case), Gadap (3 cases), North Waziristan (4 cases) and now in Mastung. On each occasion, except in North Waziristan, the response to these cases was campaigns using the oral polio vaccine (tOPV),” he said.

Dr Durray stressed that launching campaigns was the strategy for protecting children from outbreak-related cases, and strengthening routine immunisation was the foundation.

At the global level, the virus has been identified in Somalia, Nigeria and Afghanistan as well.

An official in the Prime Minister’s Polio Cell also confirmed the disturbing news, but only on the condition that he was not identified. He said that the mutated polio virus “can occur in an area with very low routine immunisation coverage”.

The response to this virus is the same as to the wild poliovirus (P1 and P3 viruses) – repeated, high-quality vaccination with oral polio vaccine.

Another high-ranking expert of the WHO, not authorised to talk to the media, told Dawn that although the latest mutated form was very close to the P2 strain of the polio virus, it could not be labeled P2.

“P2 polio virus was eradicated from the world in 1998 leaving the world with only P1 and P3” he remarked.

He explained that all the viruses were of similar types but were genetically different. However, he said all three types caused paralyses among infants.

“The tOPV is only administered to a child during routine immunisation which is held when a child is born,” said the WHO expert.

He explained that the tOPV vaccine was not used during special polio campaigns since P2 had been eradicated, and according to WHO standards in routine immunisation, tOPV was given to children only so that the P2 strain of the virus did not resurface.

Eruption of such cases from Balochistan has raised a big question mark on the overall performance of the immunisation campaigns of the federal government.

Recently, the WHO and the federal government decided to launch an emergency Supplementary Immunisation Drive (SID) throughout Balochistan, disclosed an official of the ministry of health services, regulations and coordination, not authorised to speak to the media. A round of the SIDs is planned in the province from August 19 to 21.

Once a population is fully immunised against polio, it would be protected against the spread of all strains of the poliovirus, said the official.

Sources in the PM Polio Monitoring Cell recognise that the solution is the same for all polio outbreaks: immunise every child several times, with the oral vaccine to stop polio transmission, regardless of the virus strain.

One source noted that “the lower the population immunity, the longer these viruses survive.”

In recent months, the PM Polio Cell has registered 22 polio cases in all. Most of them were reported from Fata, different parts of Khyber Pakhtunkhwa and Balochistan.

Attempts to get comments of the Federal Minister for NHSR Saira Afzal Tarar in this regard did not succeed.

Chief of the PM Polio Cell Dr Altaf Bosan was also not available for comments on the emerging dangerous situation.