Pakistan has made this year in wiping out polio. There are signs that one type of poliovirus is gone and transmission of other strains seems to be slowing, according to a report in the NPR. But a recent outbreak of polio there has health officials concerned about the overall effectiveness of the effort to eliminate polio in that country.
The World Health Organisation says 10 cases of so-called were reported in Pakistan between the end of August and the end of October.
What’s that? The oral polio vaccine contains a weakened version of the virus. In very rare instances — and when a population is not well immunised — the weakened virus can circulate in the community, mutate and infect unvaccinated people, causing paralysis. This is known as a vaccine-derived polio.
One of the big problems in the polio eradication campaign is that the cheapest, easiest to use vaccine — the oral polio vaccine — has a small risk of causing polio. An outbreak in a remote area of Pakistan which has health officials appears due to this cause.
Many experts say it is now time, with the numbers of polio cases as low as they’ve ever been, to shift to using only the injectable vaccine. It will cost more and require trained health workers but the success of this campaign to wipe out polio may depend upon it now.
Fully immunised kids are protected against both vaccine-derived and wild polio. So the problem isn’t so much with the vaccine as it is with gaps in immunization.
This is the first time that vaccine-derived polio has been detected in Pakistan. The cases appeared in the north of the province near the Afghan border.
WHO officials say the outbreak, involving a variety of the virus called type 2 polio, illustrates that vaccination campaigns in the area are failing to reach sufficient numbers of people.
Wild strains of type 2 polio were eradicated globally in 1999. However, a new strain of vaccine-derived polio emerged because the vaccine continued to contain the old type 2 viruses and it managed to spread to people who weren’t adequately immunised against it.
Vaccine-derived type 2 polio can spread in the environment in the same way as the more common type 1 or type 3. It has the same paralyzing effects on infected people as other forms of the disease.
Pakistan, Afghanistan and Nigeria are the only countries in the world where polio remains endemic.
The government of Pakistan launched an aggressive campaign this year, in partnership with international health organizations, to and carefully monitor the virus’s spread.
A previously unknown strain of polio found in two districts of Pakistan’s Balochistan province prompted recent requests to launch a polio vaccination campaign within 30 days.
Health officials reported 10 new cases of Sabin-like type 2 poliovirus in the Qilla Abdullah and Pishin districts. The outbreak is made more troubling by the presence of groups in the area that are against the anti-polio movement,
The districts are frequented by people from the troubled areas of Fata,” Zohra Yusuf, the chairperson of the Human Rights Commission of Pakistan, said. “The situation is grim because of refusal by parents to get their children vaccinated against the crippling disease as the areas are under the influence of extremist groups opposed to the anti-polio drive. The extremists belonging to Lashkar-i-Jhangvi and Tehrik-i-Taliban Pakistan have established their cells in Balochistan and warn people against vaccination of their children.”
Yusuf said an HRCP visited the two districts in May and found that people coming from Khyber Pakhtunkhwa and other tribal areas likely brought the virus with them.
