News that the world’s first bivalent polio vaccine - effective against both the P1 and P3 strains of the viral disease - is being tested in India has given new hope to health officials in Pakistan.
A controversy has been brewing in Pakistan for some weeks over the kind of vaccine used against polio, with some officials saying the World Health Organization’s (WHO’s) decision to stop P3 vaccinations had caused a rise in cases of the disease.
“The WHO stopped the P3 vaccination causing a rise in cases in 2008,” Mohammad Ali Chauhan, in charge of the polio eradication campaign in the North West Frontier Province (NWFP), was quoted as telling the media. “Thirty-three of the 52 cases of polio (in the province and Federally Administered Tribal Areas) were of the P3 virus last year,” he said.
Of the two strains of the virus, P1 is the most dangerous as it can cause huge outbreaks and travels long distances, according to health officials. It also causes paralysis in one out of every 200 infected children compared to P3, which causes paralysis in one out of every 1,000 infections. The P2 strain of the virus has not been seen since 1999, and is considered by WHO to have been eradicated.
Polio cases rising
Pakistan is locked in a battle to eradicate polio. The 118 cases reported last year, significantly higher than the total of 32 for 2007, have been followed by eight cases reported so far in 2009. This compares to only two during the same period in 2008, suggesting the count by year end could be high.
Of the cases reported this year, Melissa Corkum, communications specialist for the UN Children’s Fund (UNICEF), told IRIN regarding the government’s Expanded Programme on Immunisations: “We currently have four cases of P1 and four of P3.”
People are distressed by reports of recurring polio. “As parents, we diligently ensure all our three children are vaccinated whenever there is a drive. But if children still keep getting sick, what is the point?” asked Muhammad Haleem, a father of three, the youngest just a month old.
Controversy
WHO is using the traditional trivalent Oral Polio Vaccine (tOPV) for campaigns beginning 16-18 March. But this, too, is a matter of some controversy.
On 12 April 2007, a leading UK-based medical journal, the Lancet, published the results of a study which showed increased efficacy of the monovalent oral polio vaccine type 1 (mOPV1) over the traditionally-used tOPV against paralytic polio due to type 1 poliovirus.
Commenting on this, Melissa Corkum said: “During national campaigns we use tOPV to give full population immunity. Pakistan has both P1 and P3 viruses circulating; tOPV provides protection against both.”
Corkum further said: “Monovalent vaccines are better in building rapidly the population’s immunity against specific types of polio viruses because they are more than twice as effective as tOPV, but tOPV has the advantage of working against more than one virus type. So the decision on which type of vaccine to be used depends on careful epidemiological analysis to get the maximum benefit.”
Speaking to IRIN by phone, Oliver Rosebauer, of the WHO polio team in Geneva, said: "We are currently evaluating this. The bivalent vaccine is still under trial, but we want to know if it offers advantages when used in conjunction with the monovalent vaccine against the P1 strain of the polio virus, which is by far the most dangerous form. We don't know yet, as the results from the trials are not in. The bivalent vaccine would be used alongside the monovalent one."
Coverage vital
“Each time there is a problem with controlling disease, we start trying to deflect blame. The issue is not the vaccine, but the coverage of all children. Those of us who work on the ground know not all children are vaccinated, due not just to resistance from militants but also due to flaws in campaign structures,” Ali Yawar, a paediatrician in the city of Mansehra in the NWFP, told IRIN.
It is hoped the bivalent vaccine being tested in India can help resolve some of the problems linked to vaccine selection and thus make the battle against polio simpler.
Pakistan also remains concerned over possible transmission of the polio virus across its long border with Afghanistan, another endemic country, and has requested UNICEF to establish more vaccination centres along the border to immunise children travelling from Afghanistan to Pakistan. Meetings between health officials from both countries have also been held to coordinate anti-polio efforts.
kh/ar/cb
A controversy has been brewing in Pakistan for some weeks over the kind of vaccine used against polio, with some officials saying the World Health Organization’s (WHO’s) decision to stop P3 vaccinations had caused a rise in cases of the disease.
“The WHO stopped the P3 vaccination causing a rise in cases in 2008,” Mohammad Ali Chauhan, in charge of the polio eradication campaign in the North West Frontier Province (NWFP), was quoted as telling the media. “Thirty-three of the 52 cases of polio (in the province and Federally Administered Tribal Areas) were of the P3 virus last year,” he said.
Of the two strains of the virus, P1 is the most dangerous as it can cause huge outbreaks and travels long distances, according to health officials. It also causes paralysis in one out of every 200 infected children compared to P3, which causes paralysis in one out of every 1,000 infections. The P2 strain of the virus has not been seen since 1999, and is considered by WHO to have been eradicated.
Polio cases rising
Pakistan is locked in a battle to eradicate polio. The 118 cases reported last year, significantly higher than the total of 32 for 2007, have been followed by eight cases reported so far in 2009. This compares to only two during the same period in 2008, suggesting the count by year end could be high.
Of the cases reported this year, Melissa Corkum, communications specialist for the UN Children’s Fund (UNICEF), told IRIN regarding the government’s Expanded Programme on Immunisations: “We currently have four cases of P1 and four of P3.”
People are distressed by reports of recurring polio. “As parents, we diligently ensure all our three children are vaccinated whenever there is a drive. But if children still keep getting sick, what is the point?” asked Muhammad Haleem, a father of three, the youngest just a month old.
Controversy
WHO is using the traditional trivalent Oral Polio Vaccine (tOPV) for campaigns beginning 16-18 March. But this, too, is a matter of some controversy.
On 12 April 2007, a leading UK-based medical journal, the Lancet, published the results of a study which showed increased efficacy of the monovalent oral polio vaccine type 1 (mOPV1) over the traditionally-used tOPV against paralytic polio due to type 1 poliovirus.
Commenting on this, Melissa Corkum said: “During national campaigns we use tOPV to give full population immunity. Pakistan has both P1 and P3 viruses circulating; tOPV provides protection against both.”
Corkum further said: “Monovalent vaccines are better in building rapidly the population’s immunity against specific types of polio viruses because they are more than twice as effective as tOPV, but tOPV has the advantage of working against more than one virus type. So the decision on which type of vaccine to be used depends on careful epidemiological analysis to get the maximum benefit.”
Speaking to IRIN by phone, Oliver Rosebauer, of the WHO polio team in Geneva, said: "We are currently evaluating this. The bivalent vaccine is still under trial, but we want to know if it offers advantages when used in conjunction with the monovalent vaccine against the P1 strain of the polio virus, which is by far the most dangerous form. We don't know yet, as the results from the trials are not in. The bivalent vaccine would be used alongside the monovalent one."
Coverage vital
“Each time there is a problem with controlling disease, we start trying to deflect blame. The issue is not the vaccine, but the coverage of all children. Those of us who work on the ground know not all children are vaccinated, due not just to resistance from militants but also due to flaws in campaign structures,” Ali Yawar, a paediatrician in the city of Mansehra in the NWFP, told IRIN.
It is hoped the bivalent vaccine being tested in India can help resolve some of the problems linked to vaccine selection and thus make the battle against polio simpler.
Pakistan also remains concerned over possible transmission of the polio virus across its long border with Afghanistan, another endemic country, and has requested UNICEF to establish more vaccination centres along the border to immunise children travelling from Afghanistan to Pakistan. Meetings between health officials from both countries have also been held to coordinate anti-polio efforts.
kh/ar/cb
This article was produced by IRIN News while it was part of the United Nations Office for the Coordination of Humanitarian Affairs. Please send queries on copyright or liability to the UN. For more information: https://shop.un.org/rights-permissions
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