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And then there were two…polio-endemic countries
World Report
And then there were two...polio-endemic countries Hopes of eradicating polio rose among the global health community when WHO scratched Nigeria off the list of countries where polio has long been endemic. John Maurice reports.
Price tag Optimism that this goal will be reached rests on the historical achievements of the Global Polio Eradication Initiative (GPEI), a public–private partnership launched in 1988, when more than 350 000 children in at least 125 countries were being paralysed by the virus every year. Last year, only 359 cases were reported in only nine countries, and this year, as The Lancet went to press, only 43 cases had occurred. Achieving this 99% drop in polio cases has so far cost US$11·3 billion in financial contributions, of which $1·1 billion came from the polio-affected countries and $10·2 billion from more than 80 international donors. By comparison, ridding the world of smallpox, the first and only human disease to have been eradicated, www.thelancet.com Vol 386 October 17, 2015
cost $280 million and took only 14 years to achieve. Financial support for the polio eradication programme has so far not flagged, despite the three eradication deadlines that have been missed. The latest deadline, 2018, is also likely to be missed. WHO’s Hamid Jafari, director of Global Polio Eradication Operations and Research, explains: “Although both Pakistan and Afghanistan are making strong progress, they are unlikely to stop transmission of the poliovirus this year, but we think they can do it in 2016 if they continue to intensify their efforts. So we now aim to have polio eradication certified by 2019.” Adding that extra year, he says, is going to add $1·5 billion to the price tag.
“Financial support for the polio eradication programme has so far not flagged, despite the three eradication deadlines that have been missed.” Asked if the GPEI’s repeated failure to meet deadlines is causing donor fatigue, Donal Brown, director of the Global Funds Department at the Department for International Development in London, UK, which is one of the top three GPEI donors (equal to Rotary International) after the USA and the Bill & Melinda Gates Foundation, is adamant: “Absolutely no donor fatigue! We’re fully committed to the eradication programme and I know that most of my colleagues in the major donor agencies are also fully committed.” Brown is particularly impressed with the legacy the polio programme is bequeathing to other public health programmes. “GPEI has a massive army of vaccinators, which is being integrated into routine immunisation
systems not only for polio but also measles, yellow fever, neonatal tetanus, you name it.”
“Rocky road to zero” Amid the rejoicing that greeted Nigeria’s exit from endemicity, some polio observers introduced a cautionary note. In its May report this year, the Independent Monitoring Board (IMB), created in 2010 to keep an eye on how the eradication effort was playing out, reminded the GPEI that optimism had soared in 2012 when polio cases had plummeted but over the next 2 years a wave of major outbreaks and a surge of polio cases occurred in several countries. “The rocky road to zero...was never going to be easy”, the IMB warned. The rockiest part of the road is in the two remaining polio-endemic countries, particularly Pakistan, which accounted for 85% of the 359 wild poliovirus cases that occurred in the world last year. What’s more, Pakistan is still exporting the virus, mainly to neighbouring Afghanistan. “This intense virus transmission”, according to the latest GPEI annual report, “is now the greatest epidemiological risk to achieving a polio-free world”. The main obstacle to lowering that
Mary F Calvert/ZUMA Press/Corbis
On Sept 25, the 27-year battle to rid the world of polio took a step forward. On that day, WHO announced that Nigeria, which had reported no cases of polio caused by the wild poliovirus over the past 12 months, was no longer a polio-endemic country. Since no other African country had reported a case over the past 12 months, if thorough surveillance finds no wild poliovirus cases in the region over the next 2 years, Africa will be officially certified free of polio. Four of WHO’s six regions have already achieved that goal—the Americas in 1994, the Western-Pacific in 2000, Europe in 2002, and South-East Asia last year. The main focus of the eradication effort is now on the two remaining polio-endemic countries in the world: Afghanistan and Pakistan. Ridding them of the poliovirus will put the WHO Eastern Mediterranean region on the same footing as Africa and bring global eradication within reach.
Nigeria has reported no wild poliovirus cases for 1 year
1521
World Report
risk has been the immense difficulty of immunising children in a country ravaged by civil war and where health workers are often the targets of armed attacks. Chris Maher, manager of polio eradication for WHO’s Eastern Mediterranean region, is not unfamiliar with conflict. “My work”, he says, “covers Pakistan, Afghanistan, Syria, Iraq, Somalia, and Yemen, and I can tell you that polio teams are struggling to work in the war zones of these countries”. Adding to the difficulties are the large-scale movements of people. Displaced populations, he says, are both a bane and a blessing. “If there’s poliovirus in an area, it could move and circulate through the moving populations. At the same time, when populations are displaced from security-compromised areas, we don’t have to go door-to-door to reach children with immunisation. We can reach them when they emerge from these low-security areas.” Do the polio teams have direct contact with armed groups? “Local polio teams work with local authorities. In some areas that are not under government control we often work with networks of organised health workers who have been operating from pre-conflict days.” Reaching children in Pakistan and Afghanistan has been a critical problem. More than 700 000 children have yet to be vaccinated in these countries, according to an IMB estimate. “Those missed children are now the focus of intense scrutiny”, Jafari tells The Lancet. “Health officials in both countries are finding out where children are being missed, where parents don’t bring their children to be vaccinated, where security needs to be strengthened, and where training must be given to improve the quality of vaccination work.” One “highly successful” way of improving security that has worked in Nigeria and is being applied in Pakistan and Afghanistan, is to recruit female community volunteers who vaccinate children in their own neighbourhood. 1522
“In high-threat areas, now, the polio programme doesn’t have to recruit armed guards to protect vaccinators”, Jafari says. “The community becomes the main supporter and protector of its vaccinators.”
“‘WHO and UNICEF...have urged Ukraine’s health authorities to vaccinate all the children quickly but a month after the two cases were reported no action has yet been taken.’” Gaps in polio surveillance have also been a major hurdle to eradication in Africa and the Eastern Mediterranean regions. “This is our overarching priority now”, Jafari says. “We are improving and extending surveillance in the two regions, especially because high quality surveillance is one of the conditions of certification of eradication.”
Switching vaccine Another problem has been the ability of the live attenuated virus in the oral polio vaccine to undergo a genetic mutation that restores its virulence in the gut of the vaccine recipient. In very rare cases, when shedded in faeces, this vaccine virus can produce a polio outbreak in communities lacking strong immunity against the disease. For this reason, rich countries that have eradicated polio have switched to an injectable polio vaccine that contains killed virus and avoids the risk of vaccine-derived polio. Now, as the polio eradication endgame is being played out, every single case of polio has to be prevented, including the few vaccine-derived cases that pop up now and again. The oral polio vaccine that over the years has brought polio to its knees targets the three strains of the poliovirus—type 1, which is still circulating, type 2, which was certified last month as eradicated, and type 3, which is probably heading for eradication in the near future. The strategy the GPEI will use to
prevent vaccine-derived polio cases is for all countries that are using the three-strain (trivalent) oral vaccine to switch, by next April, to a bivalent oral vaccine which targets only two virus types, type 1 and type 3. The type 2 virus, which as a wild-type virus has been eradicated, has been causing more than 90% of vaccine-derived polio cases. With the bivalent vaccine, it will no longer be around to cause vaccine-derived polio. To boost immunity during the switch, WHO advises all countries to include at least one dose of the injectable vaccine into their routine immunisation programmes. Ultimately, following certification of global eradication, all countries should be using the injectable vaccine.
Ukrainian cases Since July last year, eleven vaccinederived polio cases have been reported in seven countries certified as polio-free. On Aug 28, Ukraine reported two cases of circulating vaccine-derived poliovirus type 1 in children. “These cases send a strong message that all countries of the world will remain at risk of polio outbreaks until all countries become polio-free”, says Dorit Nitzan, head of WHO’s country office in Ukraine. “Till then, robust surveillance and immunisation of at least 95% of the population are essential.” Last year, only 50% of children in Ukraine were vaccinated versus a European average of 96%. This year vaccine coverage dropped to 14%. “WHO and UNICEF”, Nitzan says “have urged Ukraine’s health authorities to vaccinate all the children quickly but a month after the two cases were reported no action has yet been taken”. Back in WHO’s Geneva headquarters, Jafari sums up the current status of the polio eradication drive. “All in all”, he says, “we’re very close to achieving our ultimate goal and optimism is justified. But complacency is definitely not”.
John Maurice www.thelancet.com Vol 386 October 17, 2015
And then there were two...polio-endemic countries Hopes of eradicating polio rose among the global health community when WHO scratched Nigeria off the list of countries where polio has long been endemic. John Maurice reports.
Price tag Optimism that this goal will be reached rests on the historical achievements of the Global Polio Eradication Initiative (GPEI), a public–private partnership launched in 1988, when more than 350 000 children in at least 125 countries were being paralysed by the virus every year. Last year, only 359 cases were reported in only nine countries, and this year, as The Lancet went to press, only 43 cases had occurred. Achieving this 99% drop in polio cases has so far cost US$11·3 billion in financial contributions, of which $1·1 billion came from the polio-affected countries and $10·2 billion from more than 80 international donors. By comparison, ridding the world of smallpox, the first and only human disease to have been eradicated, www.thelancet.com Vol 386 October 17, 2015
cost $280 million and took only 14 years to achieve. Financial support for the polio eradication programme has so far not flagged, despite the three eradication deadlines that have been missed. The latest deadline, 2018, is also likely to be missed. WHO’s Hamid Jafari, director of Global Polio Eradication Operations and Research, explains: “Although both Pakistan and Afghanistan are making strong progress, they are unlikely to stop transmission of the poliovirus this year, but we think they can do it in 2016 if they continue to intensify their efforts. So we now aim to have polio eradication certified by 2019.” Adding that extra year, he says, is going to add $1·5 billion to the price tag.
“Financial support for the polio eradication programme has so far not flagged, despite the three eradication deadlines that have been missed.” Asked if the GPEI’s repeated failure to meet deadlines is causing donor fatigue, Donal Brown, director of the Global Funds Department at the Department for International Development in London, UK, which is one of the top three GPEI donors (equal to Rotary International) after the USA and the Bill & Melinda Gates Foundation, is adamant: “Absolutely no donor fatigue! We’re fully committed to the eradication programme and I know that most of my colleagues in the major donor agencies are also fully committed.” Brown is particularly impressed with the legacy the polio programme is bequeathing to other public health programmes. “GPEI has a massive army of vaccinators, which is being integrated into routine immunisation
systems not only for polio but also measles, yellow fever, neonatal tetanus, you name it.”
“Rocky road to zero” Amid the rejoicing that greeted Nigeria’s exit from endemicity, some polio observers introduced a cautionary note. In its May report this year, the Independent Monitoring Board (IMB), created in 2010 to keep an eye on how the eradication effort was playing out, reminded the GPEI that optimism had soared in 2012 when polio cases had plummeted but over the next 2 years a wave of major outbreaks and a surge of polio cases occurred in several countries. “The rocky road to zero...was never going to be easy”, the IMB warned. The rockiest part of the road is in the two remaining polio-endemic countries, particularly Pakistan, which accounted for 85% of the 359 wild poliovirus cases that occurred in the world last year. What’s more, Pakistan is still exporting the virus, mainly to neighbouring Afghanistan. “This intense virus transmission”, according to the latest GPEI annual report, “is now the greatest epidemiological risk to achieving a polio-free world”. The main obstacle to lowering that
Mary F Calvert/ZUMA Press/Corbis
On Sept 25, the 27-year battle to rid the world of polio took a step forward. On that day, WHO announced that Nigeria, which had reported no cases of polio caused by the wild poliovirus over the past 12 months, was no longer a polio-endemic country. Since no other African country had reported a case over the past 12 months, if thorough surveillance finds no wild poliovirus cases in the region over the next 2 years, Africa will be officially certified free of polio. Four of WHO’s six regions have already achieved that goal—the Americas in 1994, the Western-Pacific in 2000, Europe in 2002, and South-East Asia last year. The main focus of the eradication effort is now on the two remaining polio-endemic countries in the world: Afghanistan and Pakistan. Ridding them of the poliovirus will put the WHO Eastern Mediterranean region on the same footing as Africa and bring global eradication within reach.
Nigeria has reported no wild poliovirus cases for 1 year
1521
World Report
risk has been the immense difficulty of immunising children in a country ravaged by civil war and where health workers are often the targets of armed attacks. Chris Maher, manager of polio eradication for WHO’s Eastern Mediterranean region, is not unfamiliar with conflict. “My work”, he says, “covers Pakistan, Afghanistan, Syria, Iraq, Somalia, and Yemen, and I can tell you that polio teams are struggling to work in the war zones of these countries”. Adding to the difficulties are the large-scale movements of people. Displaced populations, he says, are both a bane and a blessing. “If there’s poliovirus in an area, it could move and circulate through the moving populations. At the same time, when populations are displaced from security-compromised areas, we don’t have to go door-to-door to reach children with immunisation. We can reach them when they emerge from these low-security areas.” Do the polio teams have direct contact with armed groups? “Local polio teams work with local authorities. In some areas that are not under government control we often work with networks of organised health workers who have been operating from pre-conflict days.” Reaching children in Pakistan and Afghanistan has been a critical problem. More than 700 000 children have yet to be vaccinated in these countries, according to an IMB estimate. “Those missed children are now the focus of intense scrutiny”, Jafari tells The Lancet. “Health officials in both countries are finding out where children are being missed, where parents don’t bring their children to be vaccinated, where security needs to be strengthened, and where training must be given to improve the quality of vaccination work.” One “highly successful” way of improving security that has worked in Nigeria and is being applied in Pakistan and Afghanistan, is to recruit female community volunteers who vaccinate children in their own neighbourhood. 1522
“In high-threat areas, now, the polio programme doesn’t have to recruit armed guards to protect vaccinators”, Jafari says. “The community becomes the main supporter and protector of its vaccinators.”
“‘WHO and UNICEF...have urged Ukraine’s health authorities to vaccinate all the children quickly but a month after the two cases were reported no action has yet been taken.’” Gaps in polio surveillance have also been a major hurdle to eradication in Africa and the Eastern Mediterranean regions. “This is our overarching priority now”, Jafari says. “We are improving and extending surveillance in the two regions, especially because high quality surveillance is one of the conditions of certification of eradication.”
Switching vaccine Another problem has been the ability of the live attenuated virus in the oral polio vaccine to undergo a genetic mutation that restores its virulence in the gut of the vaccine recipient. In very rare cases, when shedded in faeces, this vaccine virus can produce a polio outbreak in communities lacking strong immunity against the disease. For this reason, rich countries that have eradicated polio have switched to an injectable polio vaccine that contains killed virus and avoids the risk of vaccine-derived polio. Now, as the polio eradication endgame is being played out, every single case of polio has to be prevented, including the few vaccine-derived cases that pop up now and again. The oral polio vaccine that over the years has brought polio to its knees targets the three strains of the poliovirus—type 1, which is still circulating, type 2, which was certified last month as eradicated, and type 3, which is probably heading for eradication in the near future. The strategy the GPEI will use to
prevent vaccine-derived polio cases is for all countries that are using the three-strain (trivalent) oral vaccine to switch, by next April, to a bivalent oral vaccine which targets only two virus types, type 1 and type 3. The type 2 virus, which as a wild-type virus has been eradicated, has been causing more than 90% of vaccine-derived polio cases. With the bivalent vaccine, it will no longer be around to cause vaccine-derived polio. To boost immunity during the switch, WHO advises all countries to include at least one dose of the injectable vaccine into their routine immunisation programmes. Ultimately, following certification of global eradication, all countries should be using the injectable vaccine.
Ukrainian cases Since July last year, eleven vaccinederived polio cases have been reported in seven countries certified as polio-free. On Aug 28, Ukraine reported two cases of circulating vaccine-derived poliovirus type 1 in children. “These cases send a strong message that all countries of the world will remain at risk of polio outbreaks until all countries become polio-free”, says Dorit Nitzan, head of WHO’s country office in Ukraine. “Till then, robust surveillance and immunisation of at least 95% of the population are essential.” Last year, only 50% of children in Ukraine were vaccinated versus a European average of 96%. This year vaccine coverage dropped to 14%. “WHO and UNICEF”, Nitzan says “have urged Ukraine’s health authorities to vaccinate all the children quickly but a month after the two cases were reported no action has yet been taken”. Back in WHO’s Geneva headquarters, Jafari sums up the current status of the polio eradication drive. “All in all”, he says, “we’re very close to achieving our ultimate goal and optimism is justified. But complacency is definitely not”.
John Maurice www.thelancet.com Vol 386 October 17, 2015