GPEI-The End of an Outbreak

Just like responding to a polio outbreak, ENDING an outbreak requires in depth data, partnerships and attention to detail. @ WHO

The detection of even a single case of polio anywhere in the world is considered an outbreak. As soon as the polio surveillance system sounds the alert that a virus has been found, an outbreak response springs into action.

But when a virus has so many possible hiding places, how can we be sure it is gone? What enables an outbreak response to be called to an end?

Ending an outbreak: on paper

According to official guidelines, an outbreak is considered to be stopped following a period of 12 months without the detection of any new polioviruses detected from any source, assuming disease surveillance meets certification standards. Once experts are confident that there are no immunity or surveillance gaps that could allow the virus to hide, the World Health Organization (WHO) removes the country from its list of re-infected or endemic countries.

Finding the needle in the haystack

These guidelines set important standards, yet carrying them out in the real world can be complicated. In Nigeria in August 2016, four wild poliovirus type 1 cases were detected. They were caused by a strain that had not been detected since 2012, due to insecurity making disease surveillance difficult in the surrounding area, enabling the virus to move unchecked.

This reminds us that guidelines – while essential – cannot do the job alone. Thorough epidemiological, operational and virological analysis is needed before interruption of poliovirus can truly be verified; and each new outbreak coming to an end must be assessed individually.

Outbreak response assessments

Every three months in outbreak countries, Outbreak Response Assessments are held by independent experts. They directly observe the implementation of all activities, analyse and verify the data and track how the outbreak is evolving – and whether the response is having an impact. They make recommendations to strengthen the continued outbreak response.

Outbreak Response Assessments provide crucial evidence for programmatic performance, risk management and evolving epidemiology. Without such assessments, we could not verify the continued presence or absence of poliovirus circulation.

Once 12 months have passed with no cases and immunization and surveillance data has been carefully scrutinised through these assessments, the outbreak response assessment committee finally draws its conclusions that the outbreak is over.

International Health Regulations

Information and conclusions from Outbreak Response Assessments are taken into consideration by the Emergency Committee of the International Health Regulations (IHR). Through the IHR, countries work together for global health security, limiting the risk that outbreaks spread across borders. In 2014, polio was declared a public health emergency of international concern under the IHR, leading to temporary recommendations which were put in place for all countries with or at risk of polio to reduce the risk of international spread.

The Emergency Committee on the Spread of Poliovirus meets every three months to review global epidemiology. They draw their own conclusions and classify countries into categories of risk. This helps to stop new outbreaks from taking place and adds an extra pair of eyes to assess when an outbreak has come to an end.

Becoming officially polio-free

Teams of independent experts assess the outbreak response. Only when no case has been found for 12 months can an outbreak be called to a close. @ WHO

The final stamp of approval that a region is polio-free only comes with regional certification. An independent Regional Certification Commission reviews data from all countries in a given region, ensuring that surveillance indicators and vaccination coverage from every single area are of the highest possible levels.

This process takes at least three years. Only when no virus has been detected anywhere in the region for a significant length of time and no doubt is left that the virus is completely gone does a region become certified as polio-free.

Only when no case of polio has been detected anywhere in the world for more than three years will the Global Certification Commission for the Eradication of Poliomyelitis meet to take a decision on whether the virus is truly gone from the world.

No room for complacency

Time, attention to detail and double checking what we know – this is what it takes to end an outbreak.

In the end, the decision to end an outbreak is only as good as the data from each remote village, each sample tested in a laboratory and each vaccination round. This makes knowledge the most powerful tool we have in the fight against polio.

Even once an outbreak has been stopped there is no room for complacency. As long as poliovirus continues to circulate anywhere in the world, countries everywhere remain at risk. As polio moves with people, any population movement to an area of low immunity can lead to a new outbreak.

Until the world has been certified polio-free by the Global Certification Commission, all countries must vaccinate every last child, find every last virus and be prepared for any outbreak.

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A child is given two drops of the oral polio vaccine to protect them against polio in Lao PDR. @ WHO/ R. Tangermann

As of May 2017, Lao People’s Democratic Republic (PDR) is officially no longer infected with circulating-vaccine derived polio virus (cVDPV), according to the International Health Regulations (IHR) Emergency Committee on the international spread of poliovirus.

After an outbreak of circulating vaccine derived poliovirus type 1 (cVDPV1) in 2015 and 2016, the country has now been without cases for over 12 months, with the last case reported in January 2016.

Since the outbreak, WHO, UNICEF and other partners have supported Lao PDR in their outbreak response efforts. This included support for multiple rounds of supplementary immunization activities, expanded social mobilization to raise community awareness and desire to vaccinate, and enhanced acute flaccid paralysis (AFP) surveillance activities to find the virus.

Ending the outbreak

In general, an outbreak is considered over following a period of 12 months without the detection of any new polioviruses from an AFP case, a healthy individual or an environmental sample, and with confirmed certification-standard disease surveillance.

An outbreak response assessment (OBRA) team visited the country in March to confirm the virus had, in fact, been stopped. The team, made up of representatives from WHO, UNICEF, and the US Centres for Disease Control and Prevention, concluded that all evidence suggested the outbreak had been successfully stopped, with all immunity and surveillance indicators meeting rigorous international standards.

At the OBRA meeting, development partners commended the Ministry of Health on its leadership in response to the outbreak. Tremendous progress was made in micro-planning, cold chain and vaccine storage at all levels, as well as nationwide social mobilization and strengthening of AFP surveillance.

Deputy Health Minister of Lao PDR, Dr. Phouthone Muangpak, noted that the Ministry of Health and local authorities need to take ownership to further improve surveillance sensitivity in the country.

Lessons from the outbreak response

Both adults and children were vaccinated through the response to make up for low levels of vaccination over an extended period of time. @ WHO /R. Tangermann

A challenging landscape and diverse ethnic communities added to the challenge of running vaccination schedules in Lao PDR. As the outbreak occurred in an area where vaccination levels had been very low for an extended period of time, campaigns were extended to reach all children under 15, and in some cases even adults. The nuanced cultural, lingual, religious and social needs of the Hmong community called for a response tailored to local needs, especially building an awareness of the importance of vaccines. Impromptu cinemas were set up against bamboo walls to pull in interested families and share information about vaccination campaigns after dark.

Find out more about the response in Lao in this photostory.

Meeting International Health Regulations standards

Information and conclusions from OBRAs are taken into consideration by the IHR Emergency Committee on the Spread of Poliovirus, resulting in this instance in the IHR classification as a state no longer infected with cVDPV1.

Despite being classified as polio-free, the IHR Emergency Committee still categorizes Lao PDR as vulnerable to reinfection. The country must continue to strengthen routine immunization to ensure all children are protected from any polio outbreak that may happen in the future and to maintain the improvements in disease surveillance, to ensure the virus is detected and stopped wherever it may emerge.

At the 70^th World Health Assembly in Geneva, global health leaders have reiterated their commitment to polio eradication, discussing progress made and challenges ahead and emphasising the critical need for effective transition planning for the post-polio era.

Member States spoke of the continuing steady progress towards eradication, and the importance of supporting the remaining endemic countries in finishing the job. With only 37 cases in three countries in 2016, achieving eradication is closer than ever before.

Delegates from Afghanistan, Pakistan, and Nigeria, the last three endemic countries, outlined their key strategies for ending transmission as a matter of priority. The Pakistani delegate underscored the need for continued support from the global community: “Last miles are difficult, but we need to stay the course and reach a significant public health landmark of our time.”

Michel Zaffran, Director of Polio Eradication at WHO, spoke of the impressive decline in cases, achieved through the commitment of Member States, and stressed the critical need to continue to support the endemic countries in their efforts to stop the virus.

“We stand on the brink of making history, but progress is fragile… We cannot lower our guard. We must redouble our efforts to support Nigeria, Pakistan and Afghanistan to implement their national emergency action plans, and ensure they have the resources to do so.”

Member States also addressed the challenge of the scale down of the polio programme as eradication comes closer, including the potential impact on achieving and sustaining a polio-free world, on health programmes and systems currently supported by polio assets, and on WHO itself. They welcomed existing efforts to plan for the post-polio world, and stressed the importance of careful, considered, and strategic approaches to the transition of polio assets, requesting the WHO Director-General to prepare a detailed transition action plan.

Many delegates expressed concern about the ongoing shortage of inactivated polio vaccine, and noted the need to implement containment measures to ensure the safe and secure storage and handling of materials containing polioviruses, and destroy unneeded materials.

Rotary International reaffirmed the commitment of their 1.2 million volunteers to the global polio eradication effort, and expressed cautious optimism about the low levels of transmission in 2017. The Rotarian speaker called for the support of all countries to achieve eradication. “The support of every country is needed now more than ever. Passive support is not enough; we will not succeed without political and financial commitment… Let’s make history and end polio together.”

WS20170207_Afghanistan — © WHO Afghanistan/ S. Ramo

Afghanistan’s long struggle to eradicate polio is showing strong signs that the country is closer than it has ever been to finally stopping the disease, once and for all.

The year 2016 ended with only 13 cases, down from 20 in 2015 and 28 in 2014. Notably, 99% of all districts ended the year polio-free, with transmission cornered in small geographical areas in the south, east and south-east of the country.

While Afghanistan this week will announce its first case of wild poliovirus for 2017 – an 11-month-old girl in Kandahar District of Kandahar Province – the country has made substantial gains that make eradication in the short term a realistic goal. Monthly campaigns will be held through the end of May during the traditional ‘low season’ for polio transmission, which provides the best opportunity to stop transmission country-wide.

Every last child vaccinated

There is reason to be cautiously confident about 2017. Last year saw notable improvements in the quality of immunization campaigns across the country – particularly in high-risk areas – with significantly more children being reached and protected than ever before. The proportion of areas achieving required coverage standards in post-campaign Lot Quality Assessment Surveys has increased over the 12 months to December 2016 from 68% to 93%. Concurrently, the quality of campaign monitoring has improved with new approaches including remote monitoring through mobile phone technology and independent third-party monitoring.

Strategic district-specific plans for 2016-2017 are focused on 47 high-risk districts responsible for 84% of polio cases in the past 7 years. An intensified community engagement communication network has been established in these districts to ensure parents and caregivers are aware of the benefits of the polio vaccine and vaccinate their children during campaigns.

A National Islamic Advisory Group for Polio Eradication has been established in 2016 and Afghan religious scholars, the Ulama, issued a Declaration calling on all Afghans to vaccinate their children. Religious leaders are now strongly involved in supporting polio eradication efforts.

A strategy to revisit homes where children were missed was introduced in 2016. By the end of the year, in areas where the Immunization Communication Network was present, teams of mobilizers were successful in vaccinating 75% of missed children in very high-risk districts.

A single block

Afghanistan and Pakistan form one epidemiological block – reaching children on the move is another priority. Coordination and joint planning between the two countries is strong. Currently, 294 Permanent Transit Teams vaccinate children who travel in and out of security-compromised areas, special campaigns target nomadic populations and 49 cross-border teams at 18 cross-border vaccination points vaccinate children when they cross into or from Pakistan and Iran. In 2016, these border teams vaccinated over 122,000 returnee children with oral polio vaccine and over 32,000 with the injectable inactivated polio vaccine.

Surveillance is king

Underpinning all eradication efforts is a surveillance system which is able to pinpoint any virus. An external surveillance review concluded in 2016 that Afghanistan’s disease surveillance surpassed global standards and circulation of the virus is unlikely to be missed. In the past 12 months, an additional 458 disease surveillance reporting sites have been introduced and the number of reporting volunteers has increased by 18% to 21,000. Three additional environmental sewage surveillance sites have been added, in Kandahar, Nangarhar and Khost, and sampling frequency has been doubled in the south.

The road ahead: neutrality

Significant challenges remain: routine immunization coverage remains weak in many areas and insecurity and active fighting has hampered vaccination teams’ access. In this complex and challenging environment, the programme continues to maintain its neutrality. Maintaining dialogue with communities remains essential.

Now more than ever, Afghanistan has all the systems in place and tools it needs to achieve eradication: high-quality immunization campaigns, strong monitoring and supervision of vaccinators, vigorous communications platforms, a strong community engagement strategy creating an enabling environment for vaccination campaigns, national and regional Emergency Operations Centres to oversee and manage the programme, a supportive civil society, religious leadership and media and – most importantly – a committed network of local health workers who are trusted and supported by their communities.

In the coming months, Afghanistan has a unique opportunity to take the world over the finishing line for polio eradication. If all elements of the polio programme are accountable for reaching and immunizing every child in high-quality monthly polio vaccination campaigns, eradication is possible.

Children in a polio free India. Photo: GPEI

Six years ago today, Rukhsar Khatoon from West Bengal became the last Indian child to be paralyzed by polio. Since that day, India has not experienced a single case of wild polio, paving the way for the South East Asia Region of the World Health Organization to be certified polio-free in 2014.

Once considered the toughest context in the world to eradicate polio, India achieved this feat through a relentless focus on reaching and immunizing every last child: it has since maintained high immunity to polio and very high quality disease surveillance, made the switch from trivalent to bivalent oral polio vaccine in its routine immunization system, and is working to transition its extensive polio eradication knowledge and assets to serve broader public health goals.

Sensitive disease surveillance and high immunity against polio remain important priorities for all countries until the remaining endemic countries stop polio for good.

New ways of delivering the inactivated polio vaccine will help get vaccines the final millimetre of their journey to protect a child against polio. © Gavi

The Global Polio Eradication Initiative is finding new ways to administer vaccines to ensure that every last child is protected against polio. From new injection devices to injection-free modes of delivery, these innovations will be crucial in resolving some of the challenges of the next few years, both approaching eradication and beyond.

Since the 1950s, the world has been vaccinating children against polio, and as a result, numbers of children paralysed by the virus have fallen from 350,000 each year down to just 74 in 2015. The opportunity to eradicate a disease is not one encountered often in global health, and the rare chance that we face to end polio forever will bring many benefits. Not least on this list is the economic dividends; by removing the poliovirus from the face of the world for good, the world will reap savings upwards of US$50 billion, funds that can be used to address other pressing public health needs.

Good things come in small packages

In the Polio Endgame, the injectable inactivated polio vaccine (IPV) will eventually be the only vaccine in use, when the oral polio vaccine (OPV) is fully phased out. Yet IPV is substantially more expensive than IPV – up to 15 times per dose – and it is also harder to deliver, needing trained professionals to give the injection. In addition, global supply constraints stand in the way of the important task of ensuring that every child worldwide is receiving this vaccine.

Building on a growing body of research that shows IPV can be given in fractional doses, the Strategic Advisory Group of Experts on immunization (SAGE) recommended this October that countries consider using 1/5 of a dose delivered intradermally in both routine immunization schedules and vaccination campaigns. India and Sri Lanka have already adopted this methodology.

This innovative approach would reduce the cost of using IPV in the future, once OPV has been withdrawn from use. This is important: as even once eradication has been achieved, maintaining high immunity will be necessary for some years, in case of a circulating vaccine-derived poliovirus outbreak or a containment breach of a virus from a vaccine manufacturer or laboratory.

But developments to ensure that every child can receive the benefits of being vaccinated against polio have not stopped at reducing cost.

Making it easier to reach every last child

Fractional doses of IPV need to be delivered intradermally into the top layer of the skin, rather than into the muscle. This requires different administration methods, training and tools to deliver it, although all other aspects of storage and handling are the same. Until now this has been done using the needle typically used to deliver the BCG vaccine, which is short and narrow, making it easier it get the vaccine between the skin layers. This can be a challenge for health care workers used to deliver IPV into the muscle.

When the inactivated polio vaccine is delivered intradermally, 1/5 of a dose generates nearly as much immunity as one full dose delivered into the muscle. © WHO

But new delivery devices could simplify this work, reducing one of the barriers to administration of fractional dose IPV. This could greatly alleviate the global IPV supply constraint, by maximising all available vaccine supply and enabling more children to be reached with it.

Needle-free injectors

Following clinical trials, WHO has started stockpiling the Tropis needle-free injector, a device that can deliver the vaccine through a narrow, precise stream of fluid that penetrates the skin without the use of a needle, whilst still delivering a similar quality as the BCG needle.

Though health workers will still need special training, the use of these devices could make their lives much easier by making some of the huge advantages that applied to the oral polio vaccine available for IPV as well.

Micropatch needles

A second innovation could also potentially transform IPV delivery. Micropatch needles are also being researched, coming with the advantage that they could be delivered not only by healthcare professionals, but also by trained volunteers, like OPV. Each patch, about a square inch in size, contains 100 vaccine-filled needles each the diameter of a human hair. When pressed into the skin, the needles dissolve, leaving only the patch backing. This approach would also revolutionise GPEI’s ability to deliver IPV as quickly and easily as OPV. Being able to carry out house-to-house vaccination campaigns would be a game-changer, especially in areas where reaching every last child can be a challenge. WHO is looking forward to clinical studies to evaluate this new approach.

The Global Polio Eradication Initiative (GPEI) is highlighting the innovations that are helping to bring us closer to a polio-free world. Find out about other new approaches driving the polio eradication efforts by reading more in the Innovation Series.

As the GPEI moves closer to eradication, the original vaccine against polio – the inactivated polio vaccine (IPV) – is playing a central role in immunizing children against polioviruses. By finding innovative methods of delivering the vaccine in a fractional dose, the GPEI is exploring new ways to overcome global supply constraints, and could help to bring the benefits of IPV to children everywhere.

The role of IPV in the Polio Endgame

Thanks to major steps forward including the declaration of wild poliovirus type 2 as eradicated in September 2015, the phased removal of oral polio vaccines began in April 2016 with the withdrawal of the type 2 component. As an essential part of this, all countries agreed to introduce one dose of IPV into their routine immunization systems to boost immunity against poliovirus types 1 and 3 and provide a baseline of immunity against type 2 in case of an outbreak of type 2 vaccine derived polioviruses.

Despite the importance of this step towards the Endgame, there are challenges facing IPV introduction. Shortfalls in IPV supply globally have left more than 40 countries without sufficient IPV supply to vaccinate all children through their routine immunization systems.

Fractional dose IPV is an innovation that could help address this challenge.

Fractional dose IPV

Full dose IPV is delivered through an intramuscular injection. But IPV can also be given intradermally, into the skin. When delivered in this way, only 1/5 of a dose is needed to generate almost as much immunity as one full dose delivered into the muscle; and two fractional doses generates higher immunity than one full dose. This innovation is making financial savings by reducing the cost of IPV, and enabling the limited supply to go much further.

Rolling out fractional dose IPV

The feasibility of using this new approach to delivering IPV is supported by a growing body of research. This has led to the recommendation of the Strategic Advisory Group of Experts on immunization (SAGE) for countries to consider adopting fractional dose IPV in both their supplementary and routine immunization activities.

A new field study in Sri Lanka provided evidence that using fractional dose IPV is as effective as using a full dose in OPV primed populations to boost mucosal immunity. This joins a body of previous studies that had already shown it to be as effective as full dose at inferring humoral immunity. Mucosal immunity is critical in stopping the person-to-person spread of virus.

Further research is showing that this approach to IPV delivery can be used for both routine immunization and outbreak response, meaning that the supply that is available can be maximised. A recent pilot campaign in Pakistan gathered data on its use in campaigns, which led to the GPEI recommending its use in outbreak response to boost immunity alongside OPV. A few countries are already adopting this new approach. Recent campaigns in India and Pakistan gathered data on its use in campaigns, which demonstrated feasibility in outbreak response to boost immunity alongside OPV. In addition, India and Sri Lanka are beginning to use fractional dose IPV in their routine immunization schedules. More countries are to follow in the face of the global IPV shortage.

The GPEI is also continuing to explore additional delivery mechanisms to overcome potential operational challenges, such as adaptors and needle-free devices to make it easier to deliver the vaccine intradermally. With the progress being made in this arena, the benefits fractional dose IPV could provide for children far outweigh any challenges.

Building trust

In a statement issued from the meeting, the IAG stated that it “… reiterates its trust in the safety and effectiveness of polio and other routine childhood vaccinations as a life-saving tool which protects children; and acknowledge that it fully conforms to Islamic rulings.” This stance from the IAG has played a crucial role in addressing the need for trust building, reliable information relating to vaccines, and accessibility issues in reaching every last child in immunization campaigns in several Muslim countries.

The IAG also affirmed the religious obligation of parents to vaccinate their children to keep them healthy. Dr. Saleh Bin Abdallah Bin Humaid, President of the IIFA reminded meeting participants of Prophet Mohammed’s call to Muslims that they should “seek treatment, O worshippers of God, for God did not send down an illness except having sent down a medicine for it apart from ageing.”

Continuing support

Dr Alwan also commended the role of the governments of Pakistan and Afghanistan for their efforts to eradicate polio, an effort which came about partially through the support of the Islamic Development Bank.

“The bank has provided technical grants to support the efforts of the Somali government and the partners in order to control the outbreak of polio which spread across the Horn of Africa in 2013,” said Dr. Ahmad Mohamed Ali, President of the Islamic Development Bank. “It has also provided an additional US$100 million of funds to support the efforts of the Pakistani government and the partners in order to eradicate polio by the end of 2018, with the Will of Allah.”

Expanding their Role

At the 13th Islamic Summit Conference held in Istanbul in April 2016, leaders of the OIC recommended that mother and child health priorities also need to be addressed in order to bring down maternal and child mortality.

“Building on the successful experience in improving polio immunization services, the Islamic Advisory Group is now well placed to further help promote health care in the Muslim countries, which still carry a heavy burden of preventable causes of mortality and morbidity,” Ambassador Mohammed Naeem Khan, Assistant Secretary General of the OIC for Science and Technology told IAG members on behalf of Secretary General Mr. Iyad Ameen Madani.

The IAG was launched in 2013 after consultations between the International Islamic Fiqh Academy (IIFA), Al Azhar Al Sharif, the Islamic Development Bank (IsDB), and the Organisation of Islamic Cooperation (OIC). The leaders of these organizations, as well as other religious scholars, technical experts and academics from the Muslim World all participated in the IAG.

As a reflection of this recommendation the IAG stressed “the need for this group to promote and influence better health outcomes for families, particularly mothers and children, and commit to expanding the scope of this Group to address other key mother and child health interventions.”

The past year has been marked by defining events that show us to be closer than we have ever been to achieving the goal of polio eradication. One such milestones was one of the biggest globally coordinated projects in the history of vaccines: the withdrawal of the type two component of the oral polio vaccine through the switch from trivalent to bivalent oral polio vaccine (OPV) in 155 countries and territories.

The goal of eradicating polio is one that has pulled together countries, donors, politicians, traditional leaders and families for nearly three decades, since the origins of the Global Polio Eradication Initiative (GPEI) in 1988. Taking the world one huge step forwards towards the eventual removal of all oral polio vaccine, the switch will help to reinforce immunity against the remaining types of polioviruses and greatly reduce the risk of vaccine-derived cases.

Referring to the OPV switch in her opening address to the 69^th World Health Assembly (WHA) in May, Dr Margaret Chan, the Director General of WHO, offered her thanks to countries for what she described as a ‘marvellous feat’.

A Global Achievement

After many months of coordination, planning, training, procurement efforts, and logistical preparations, the switch is now complete. To confirm that trivalent oral polio vaccine is no longer being used, almost all countries have submitted their national validation reports, with the remaining few in the final stages of clearance. Based on initial analysis, the volumes of trivalent OPV disposed as a result of the switch have been minimised, due to overall strong advance planning and activities such as inventory assessments.

Why the switch matters for polio eradication

Thanks to the trivalent oral polio vaccine, more than 16 million children are walking today who would otherwise have been paralysed for life. Giving protection against all three types of the virus, it led to the eradication of type two wild poliovirus, confirmed in September 2015, and to three years passing since the last case of type three was reported in 2012. With type one wild poliovirus remaining in just two countries – Pakistan and Afghanistan – and case numbers at an all-time low, the world is closer than it has ever been to getting rid of polio for good.

However, this decrease in cases of wild polioviruses has shifted the focus of the GPEI to placing an equal emphasis on vaccine derived polioviruses, which in very rare cases when routine immunization levels are low can mutate from the attenuated virus originally contained in the oral polio vaccine. In 2015, cases of vaccine derived polioviruses were found in more countries than wild poliovirus cases – a sign of significant progress towards stopping wild polio, and also a reminder of the importance of withdrawing the oral polio vaccine in a phased manner (beginning with the switch), as outlined in the Polio Eradication and Endgame Strategic Plan.

In the last ten years, 90% of vaccine-derived poliovirus cases evolved from the type 2 component in the oral polio vaccine. Additionally, more than 200 cases of vaccine-associated paralytic polio (VAPP) were caused by this component every year. These statistics, alongside the declaration of the eradication of type two wild poliovirus last year, provided the momentum for the withdrawal of the type two component of the oral polio vaccine through the trivalent to bivalent switch.

What next?

There is still much to do. While the switch will eventually remove the threat of type 2 circulating vaccine derived polioviruses for future generations, there are important risk mitigation measures that need to be taken to ensure that no type two poliovirus can ever again pose a threat to children. The global contingency plans that have been put in place were appreciated by many delegates at the WHA, especially in light of the global supply shortage of the inactivated polio vaccine.

First of all, outbreak response plans are being put in place to protect against strains of type two vaccine derived poliovirus should such strains emerge from type two oral polio vaccines used up until the switch, if allowed to circulate and mutate in areas with low levels of immunity. A global stockpile of monovalent oral polio vaccine type two is in place in case such outbreak occurs, to rapidly build immunity against type two in the surrounding area. Finally, containment measures are being carried out to ensure the safe handling of type 2 viruses in vaccine manufacturing facilities or laboratories.

Progress for Public Health

Delegates at the polio session of the WHA praised the execution of the switch, emphasising the importance of this step for public health. Michel Zaffran, Director of Polio Eradication at WHO stated: “The switch marks how far we have come; and will take us even further towards stopping vaccine derived polioviruses.”

Last week, global political commitment to eradicating polio was affirmed at the World Health Assembly (WHA) in Geneva. During the polio agenda item, member states discussed progress made in the last year and the remaining hurdles that stand in the way of polio eradication.

In her opening address to the WHA, Dr Margaret Chan, Director General of WHO, said polio eradication has never been so close to the finish line. “During the short span of 2 weeks in April, 155 countries successfully switched from trivalent to bivalent oral polio vaccine, marking the largest coordinated vaccine withdrawal in history. I thank you and your country teams for this marvellous feat,” she said.

Member states reviewed the latest global epidemiology, noting the strong progress made across Africa with no case of wild poliovirus in approaching two years. Delegates from Afghanistan and Pakistan, the final remaining polio endemic countries, outlined the steps they are taking to ensure that transmission is interrupted as a matter of urgency. With fewer missed children than ever before and just 74 cases across the two in 2015, achieving eradication has never appeared to be such an achievable target.

Many member states spoke to reaffirm their commitments to fulfilling the objectives of the resolution passed at the last WHA to commit to ending polio once and for all. Michel Zaffran, Director of Polio Eradication at WHO, stated that strong progress had been made against all four objectives of the Polio Eradication and Endgame Strategic Plan.

Delegates also commended the historic achievement of the switch, warning that shortages of the inactivated polio vaccine and potential outbreaks of type 2 vaccine-derived polioviruses would be some of the major challenges of the coming year. They also expressed appreciation for the global contingency plans put in place to adequately manage the risks associated with the supply shortage, notably the availability of the stockpile of monovalent oral polio vaccine type 2.

Gavi, the Vaccine Alliance, supported the interjections of several member states highlighting the importance of ramping up transition planning in countries to prepare for the end of the polio infrastructure after eradication. “To be sustainable, the decision on which polio assets to sustain must be fully led and driven by countries themselves, based on national ownership, national plans and investments,” said the Gavi spokesperson.

Rotary international spoke to affirm that their 1.2 million volunteers worldwide remain fully committed to polio eradication. “We have three key challenges remaining,” said the Rotarian speaker. “First, we have to interrupt polio in Pakistan and Afghanistan. Second, we must avoid complacency. An additional US $1.5 billion is needed through 2019 to sustain high levels of immunity, repeatedly reaching more than 400,000,000 children in up to 60 countries and carrying out high quality surveillance to protect progress. Finally we must fully leverage the physical and intellectual assets of polio eradication so that they can benefit broader public health priorities.”

The World Health Organization’s Global Polio Eradication Initiative (WHO/POL) is looking for Expressions of Interest from private or public sector vaccine manufacturers in developing countries interested in collaborating with WHO and Intravacc in the development, manufacture and distribution of a safe effective and affordable Sabin Inactivated Polio Vaccine (sIPV), that can be produced securely in developing country settings.

Call for Expressions of Interest

Iraq has become the 156th country to introduce the inactivated poliovirus vaccine (IPV) into its routine immunization schedule, a laudable achievement given the country’s current situation.

IPV will be given to children when they are 2, 4 and 6 months old, in a combination vaccine which also infers protection against diphtheria, tetanus, whooping cough, hepatitis B and Haemophilus influenzae type B.

The introduction of IPV comes two months before the trivalent to bivalent oral polio vaccine (OPV) switch, which will see the removal of the type 2 component from OPV. Polio eradication efforts have led to the eradication of wild poliovirus type 2, enabling this removal, the first step in the phased removal of all oral polio vaccine.
Iraq reported its last case of indigenous wild poliovirus in 2000, but suffered an outbreak in 2014, related to a strain isolated in Syria. The outbreak was successfully bought to a close, with the second and final case of the outbreak reported in April 2014.

While IPV introduction marks promising progress for Iraq, more work needs to be done. Routine immunization coverage has fallen over the last few years, from a high of 80% in 2011 to an estimate 63% in 2014. Surveillance for Acute flaccid paralysis (AFP) – one of the signs of polio – remains strong nationally, but gaps persist in areas of the country.

The introduction of IPV in routine immunization is a huge success for Iraq and will help to secure a world in which no child is ever again paralysed by polio

Related resources

Shri J P Nadda, the Union Minister for Health and Family Welfare, launched the injectable Inactivated Polio Vaccine (IPV) in India in November, announcing that “… at this momentous milestone, India remains committed to Global Polio Eradication.”

The Health Minister stated that in a landmark step to provide double protection to our children and securing our gains of polio eradication, the Government of India is introducing one dose of IPV into its routine immunization program alongside the oral polio vaccine. The vaccine will initially be introduced in six states: Assam, Gujarat, Punjab, Bihar, Madhya Pradesh, and Uttar Pradesh. New evidences now clearly show that IPV and OPV together will further strengthen the children’s immune system and will provide double protection against polio, explained the Health Minister.

The South East Asia and Pacific region was declared polio-free in 2014 after three years with no cases in India. Yet with bordering Pakistan still reporting cases of polio, the introduction of IPV into routine immunization programmes will provide an important boost to the immunity of children in India against all types of poliovirus.

By the end of the year, more than 80 % of the global birth cohort will be routinely receiving due to the largest globally synchronised vaccine introduction in history.

“We are utilizing the opportunities to intensify our efforts to ensure full immunization of all children in the country. Every new vaccine introduction gives us the added opportunity of health system strengthening. As part of this introduction we have trained our health officials and frontline health workers”, Shri J P Nadda said.

The Health Minister thanked and congratulated all state governments and the supporting organizations like WHO, UNICEF and Rotary International etc. for partnering in this endeavour. He expressed his gratitude toward the frontline health workers for achieving unique success of polio eradication in the sphere of public health.

Smt. Poonam Khetrapal, Regional Director, SEARO (WHO) stated that launching IPV in India is a historic moment and will further cement India’s achievements on polio to date. She said it is necessary step to eradicate polio virus from the world. She also applauded the Government of India for its commitment to eradicate polio.

Mr. Michael McGovern, International PolioPlus Committee of Rotary International commended India for its success in keeping the country polio-free, and said that Rotary will always support the country’s polio eradication efforts. Rotarians across India played an essential role in stopping polio in India, and are making just as important a contribution to keeping the country polio-free.

Mr. Louis-Georges Arsenault, UNICEF Representative for India commended the strengthening of India’s immunization programme by introduction of IPV and termed this as a “monumental step”. He reiterated commitment and support of UNICEF in India’s immunization endeavors.

The Bill & Melinda Gates Foundation, Norway, and the United Kingdom are generously supporting the introduction of IPV in routine immunisation schedules in 72 Gavi-supported countries, while Canada is supporting its introduction in other lower-middle income countries. The top ten government donors to GPEI include the USA, the UK, Japan, Germany, Canada, the Netherlands, Norway and Australia.

The Global Polio Eradication Initiative (GPEI) is led by national governments and spearheaded by the World Health Organization (WHO), Rotary International, the US Centers for Disease Control and Prevention (CDC), and the United Nations Children’s Fund (UNICEF), with the support of the Bill & Melinda Gates Foundation.

Since its launch at the World Health Assembly in 1988, the GPEI has reduced the global incidence of polio by more than 99%. The GPEI receives financial support from governments of countries affected by polio; private sector foundations, donor governments, multilateral organizations, private individuals, humanitarian and nongovernmental organizations and corporate partners.

Dr Jonas Salk with one of the first children to receive the vaccine. © WHO — Dr Jonas Salk with one of the first children to receive the vaccine.
© WHO

Some moments in history carry a greater significance than others. Sixty years ago on the 12^th of April, a vaccine developed by Jonas Salk proved to be safe and effective in protecting children against polio. This gave the world one of the critical tools needed to begin the fight against the crippling disease. Since then, the polio programme has been one of the most successful public health programmes in history, reducing polio cases reduced by 99%. Now, the final 1% is tantalizingly within reach. As we commemorate Jonas Salk’s remarkable achievement, the vaccine that began this journey – the inactivated polio vaccine (IPV) – is playing an important role in the final steps towards eradication, and ensuring that the virus will never be able to return.

An incurable threat

For thousands of years, polio was a leading cause of disability, arriving without warning and causing lifelong paralysis. Against the backdrop of increasingly devastating outbreaks in the United States, Jonas Salk was born in 1914. In 1916 alone, over 27 000 people were paralyzed and 6 000 killed in America.

In 1928, with ever-higher numbers of cases, iron lungs were introduced to help patients breathe, keeping many alive who would have died only years before. Yet, in many cases, this restricted otherwise healthy people to a life of reliance on these machines.

The discovery that changed the world

In 1908, Dr Karl Landsteiner discovered that polio is caused by a virus. This marked the start of several decades during which understanding of the disease began to grow, setting the stage for scientists to begin to work on a way to prevent it.

At the New York University School of Medicine in 1938, Dr Jonas Salk began to work on an influenza vaccine. Here he learned techniques that would later enabled him to develop the inactivated polio vaccine at the virus research program he launched at the University of Pittsburgh in 1947.

By 1952, Salk and his colleagues announced that they had developed an injectable vaccine against polio. Following small trials in the Pittsburgh area of the United States, Canada, the US and Finland launched trials on an unprecedented scale, involving 1.8 million children. Finally, in April 1955, Salk’s vaccine was declared “safe, effective and potent.” By 1957, cases in America had dropped by almost 90%, and by 1979, stopped altogether.

With the development of the oral polio vaccine (OPV) by Dr Albert Sabin in 1961, the world was given the tools to both stop outbreaks, and strengthen and build immunity to ensure that children could grow up without the threat of polio.

A global focus

Despite the dramatic impact of the vaccine in America, polio continued to affect some 350,000 people in 125 countries around the world. In 1988, driven by Rotary International who had become crucial advocates in the fight against polio, the World Health Organization, UNICEF, and the U.S. Centers for Disease Control and Prevention joined Rotary to launch the Global Polio Eradication Initiative (GPEI).

Since then, the GPEI has supported governments to end transmission of polio globally. The combination of the oral polio vaccine and IPV led to the eradication of polio in the Americas, in the Western Pacific, and Europe. With the declaration of the WHO’s South-East Asia Region as polio-free in 2014, 80% of the world’s populations now live in polio-free regions – a public health milestone that was unimaginable when Salk first began his work on vaccines.

The role of the inactivated polio vaccine today

Now, on 12 April 2015, as we celebrate the 60^th anniversary of the introduction of Salk’s IPV we are reminded of more than 10 million people walking today who would otherwise have been paralyzed by polio.

In the past six months, just two countries have reported cases of wild poliovirus: Afghanistan and Pakistan. As a polio-free world comes into sharper focus, Salk’s vaccine is once again demonstrating its importance. In 2015, 120 countries are introducing his IPV into their routine immunization systems (some countries, like Nigeria, already have). With the phased removal of OPV crucial in order to completely eradicate all polioviruses, reaching all children with IPV will be essential in securing the gains made against polio for future generations.

In China, oral polio vaccine is administered in candy-coated formulation WHO/S Roesel

The Ministry of Health, China, has informed WHO that wild poliovirus type 1 (WPV1) has been isolated from four young children, aged between four months and two years, with onset of paralysis between 3 and 27 July 2011. All four cases are from Hotan Prefecture, Xinjiang Uygur Autonomous Region, China. Genetic sequencing of the isolated viruses indicates they are genetically-related to viruses currently circulating in Pakistan. The last WPV case in China was reported in 1999, due to an importation from India. The last indigenous polio case occurred in China in 1994.

A national team of clinicians, laboratory experts, epidemiologists and public health experts has been dispatched to the affected region, to assist in the investigation and planning of response activities, and this team will be joined by international support as required. National, Xinjiang Uygur Autonomous Region and local public health authorities are currently conducting an epidemiological investigation, including collection of stool specimens from contacts and evaluation of vaccine coverage.

The Ministry of Health plans to conduct an initial response vaccination campaign in early September, targeting 3.8 million children aged under 15 years in the key affected outbreak area, and children aged under 5 years in other areas of Xinjiang.

To minimise the risks of acquiring polio (for travellers to infected areas) and of reinfection of polio-free areas (by travellers from infected areas), the World Health Organization (WHO) has updated its polio immunization recommendations for travellers in its publication, International travel and health 2011.

All travellers to and from countries or areas reporting wild poliovirus should be adequately vaccinated. Travellers to countries or areas reporting indigenous wild poliovirus who have previously received three or more doses of oral polio vaccine (OPV) or inactivated polio vaccine (IPV) should be offered another dose of polio vaccine as a once-only dose before departure. Non-immunized individuals intending to travel to these countries or areas should complete a primary schedule of polio vaccination, using either IPV or OPV.

Individuals living in countries or areas reporting indigenous wild poliovirus should have completed a full course of vaccination against polio, preferably with OPV, before travelling abroad. Such travellers should receive an additional dose of OPV 1-12 months before each international journey.

In case of urgent travel, a minimum of one dose of OPV should be given, ideally four weeks before departure.

For more, click here: International travel and health 2011.

Tajikistan has held four rounds of vaccination activities in response to an outbreak of polio now totalling 183 paralyzed children (as of 8 June), and at least one further round is planned. The number of cases reported has started to decline following the mass vaccinations.

Neighbouring countries continue to take precautionary measures: Uzbekistan has held two nation-wide campaigns with reportedly high coverage of children; children living in the bordering provinces of Afghanistan have been vaccinated twice since the outbreak was reported in Tajikistan: in Russia, control measures and heightened surveillance are in place.

The size of the outbreak in Tajikistan means that it outstrips all other polio-affected countries, accounting for more than two-thirds of all polio cases in the world this year. Until polio is eradicated, any country is at risk of an importation, and high population immunity is the only protection against a large outbreak.

Tajikistan is in the European Region of the World Health Organization, certified polio-free in 2002. Three of the four remaining polio-endemic countries in the world are close to or bordering Tajikistan: Afghanistan, India and Pakistan. The poliovirus that has caused the Tajikistan outbreak is of Indian origin.

Reporting from the latest campaign in Uzbekistan
Epidemiological updates from WHO European Region

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