Musculoskeletal System Diseases


Key Facts:

  • Polio (poliomyelitis) mainly affects children under five years of age, but it may affect unvaccinated adults as well.
  • Polio is a fast spreading viral infection, with no symptoms in most cases.
  • One in 200 infections leads to irreversible paralysis (usually in the legs). Among those paralyzed, 5% to 10% die when their breathing muscles become immobilized.
  • Polio cases have decreased by over 99% since 1988, from an estimated 350 000 cases then, to 1997 reported cases in 2006. The reduction is the result of the global effort to eradicate the disease.
  • In 2010, only four countries in the world remain polio-endemic, down from more than 125 in 1988. The remaining countries are Afghanistan, India, Nigeria and Pakistan.
  • Persistent pockets of polio transmission in northern India, northern Nigeria and the border between Afghanistan and Pakistan are the current focus of the polio eradication initiative.
  • As long as a single child remains infected, children in all countries are at risk of contracting polio. Between 2003 and 2005, 25 previously polio-free countries were re-infected due to imports of the virus.
  • In most countries, the global effort has expanded capacities to tackle other infectious diseases by building effective surveillance and immunization systems. Knowledge of the poliovirus has expanded with aggressive research carried out under the eradication effort.
  • Success for the effort hinges on closing a substantial funding gap to finance next steps of the global eradication initiative.

What Is Polio?

Polio is a highly infectious viral disease, which mainly affects young children. The virus is transmitted through contaminated food and water, and multiplies in the intestine, from where it can invade the nervous system. Many infected people have no symptoms. In a small proportion of cases, the disease causes paralysis, which is often permanent. Polio can only be prevented by immunization.

  • Approximately 95% of persons infected with polio will have no symptoms.
  • About 4-8% of infected persons have minor symptoms, such as fever, fatigue, nausea, headache, flu-like symptoms, stiffness in the neck and back, and pain in the limbs, which often resolve completely.
  • Fewer than 1% of polio cases result in permanent paralysis of the limbs (usually the legs).
  • Of those paralyzed, 5-10% die when the paralysis strikes the respiratory muscles.
Paralysis that can lead to permanent disability and death.
Polio is spread by person-to-person contact and only affects humans.


There are two types of vaccine that can prevent polio:

  • Inactivated Polio Vaccine -IPV
  • Oral Polio Vaccine-OPV

Who Needs to be Vaccinated?

Does my infant or child need this vaccine?

Children should be vaccinated with 4 doses of inactivated polio vaccine (IPV) at the following ages:

  • A dose at 2 months
  •  A dose at 4 months
  • A dose at 6-18 months
  • A booster dose at 4-6 years
    As an adult, do I need this vaccine?

Most adults do not need polio vaccine because they were already vaccinated as children. But three groups of adults are at higher risk and should consider polio vaccination in the following situations:

  • You are traveling to polio-endemic or high-risk areas of the world.
  • You are working in a laboratory and handling specimens that might contain polioviruses.
  • You are a healthcare worker treating patients who could have polio or have close contact with a person who could be infected with poliovirus.
  • Adults in these three groups who have never been vaccinated against polio should get 3 doses of IPV:
    • The first dose: at any time,
    • The second dose: 1 to 2 months later,
    • The third dose: 6 to 12 months after the second.
There is no cure for polio, it can only be prevented. Polio vaccine, given multiple times, can protect a child for life.
Global Caseload:
Polio cases have decreased by over 99% since 1988, from an estimated 350 000 cases in more than 125 endemic countries then, to 1604 reported cases in 2009. In 2010, only parts of four countries in the world remain endemic for the disease - the smallest geographic area in history - and case numbers of wild poliovirus type 3 are down to lowest-ever levels.
The Global Polio Eradication Initiative
In 1988, the forty-first World Health Assembly, consisting then of delegates from 166 Member States, adopted a resolution for the worldwide eradication of polio. It marked the launch of the Global Polio Eradication Initiative, spearheaded by WHO, Rotary International, the US Centers for Disease Control and Prevention (CDC) and the United Nations Children’s Fund (UNICEF). This followed the certification of the eradication of smallpox in 1980, progress during the 1980s towards elimination of the poliovirus in the Americas, and Rotary International’s commitment to raise funds to protect all children from the disease.

Overall, since the Global Polio Eradication Initiative was launched, the number of cases has fallen by over 99%. In 2010, only four countries in the world remain polio-endemic. Persistent pockets of polio transmission in northern Nigeria and along the border between Afghanistan and Pakistan are key epidemiological challenges.
In 1994, the WHO Region of the Americas (36 countries) was certified polio-free, followed by the WHO Western Pacific Region (37 countries and areas including China) in 2000 and the WHO European Region (51 countries) in June 2002. In 2010, the European Region suffered its first importation of polio after certification. In 2011, the WHO Western Pacific Region also suffered an importation of poliovirus. 
In 2009, more than 361 million children were immunized in 40 countries during 273 supplementary immunization activities (SIAs). Globally, polio surveillance is at historical highs, as represented by the timely detection of cases of acute flaccid paralysis.


  • to interrupt transmission of wild poliovirus as soon as possible;
  • to achieve certification of global polio eradication;
  • to contribute to health systems development and strengthen routine immunization and surveillance for communicable diseases in a systematic way.

There are four core strategies to stop transmission of the wild poliovirus in areas that are affected by the disease or considered at high risk of re-infection:

  • High infant immunization coverage with four doses of oral poliovirus vaccine (OPV) in the first year of life.
  • Supplementary doses of OPV to all children under five years of age during SIAs.
  • Surveillance for wild poliovirus through reporting and laboratory testing of all acute flaccid paralysis (AFP) cases among children under fifteen years of age.
  • Targeted “mop-up” campaigns once wild poliovirus transmission is limited to a specific focal area.

Before a WHO region can be certified polio-free, three conditions must be satisfied:

  • There are at least three years of zero polio cases due to wild poliovirus.
  • Disease surveillance efforts in countries meet international standards.
  • Each country must illustrate the capacity to detect, report and respond to “imported” polio cases.

Laboratory stocks must be contained and safe management of the wild virus in inactivated polio vaccine (IPV) manufacturing sites must be assured before the world can be certified polio-free.
The Independent Monitoring Board (IMB) will evaluate on a quarterly basis the progress towards each of the major milestones of the Global Polio Eradication Initiative Strategic Plan 2010-2012, determine the impact of any 'mid-course corrections' that are deemed necessary, and advise on additional measures when appropriate.

The Global Polio Eradication Initiative (GPEI) is spearheaded by WHO, Rotary International, CDC and UNICEF. The eradication of polio is about equity in health and the moral imperative of reaching every child with an available health intervention.
The polio eradication coalition includes governments of countries affected by polio; private sector foundations (e.g. United Nations Foundation, Bill & Melinda Gates Foundation); development banks (e.g. the World Bank); donor governments (e.g. Australia, Austria, Belgium, Canada, Denmark, Finland, France, Germany, Iceland, Ireland, Italy, Japan, Luxembourg, Malaysia, Monaco, the Netherlands, New Zealand, Norway, Oman, Portugal, Qatar, the Republic of Korea, the Russian Federation, Saudi Arabia, Spain, Sweden, Switzerland, Turkey, United Arab Emirates, the United Kingdom and the United States of America); the European Commission; humanitarian and nongovernmental organizations (e.g. the International Red Cross and Red Crescent societies and the Global Poverty Project) and corporate partners (e.g. Sanofi Pasteur and Wyeth). Volunteers in developing countries also play a key role: 20 million people have participated in mass immunization campaigns.


Priorities for Polio Eradication:

As long as a single child remains infected with polio, children in all countries are at risk of contracting the disease.

To stop transmission of the wild poliovirus and optimize the benefits of polio eradication, the global priorities are:

  • Closing the Funding Gap:
    Substantial financial resources are required to support polio eradication. However, in addition to the obvious humanitarian benefits, economic modelling has demonstrated the financial benefits of polio eradication to be at least US$ 40-50 billion. Success in carrying out the necessary vaccination campaigns and surveillance hinges on sufficient funds from financial stakeholders.
  • Stopping Wild Poliovirus Transmission in Endemic Countries:
    Polio today is more geographically restricted than ever before. The highest priority is reaching all children during SIAs in the four countries which have never stopped transmission of polio. To succeed, high levels of political commitment must be maintained at national, state/provincial and district levels. In 2010, a new strategic plan was launched, based on lessons learned in the past years and an independent evaluation of the major barriers to stopping polio transmission. This strategic plan is based on district-specific planning to address the unique challenges of each of the infected areas, fully exploiting new tools such as bivalent oral polio vaccine and strengthening health systems.

Impact of the Initiative:
More than eight million people who would otherwise have been paralysed are walking today because they have been immunized against polio since the initiative began in 1988.
By preventing a debilitating disease, the Global Polio Eradication Initiative is helping reduce poverty, and is giving children and their families a greater chance of leading healthy and productive lives.
By establishing the capacity to access children everywhere, more than two billion children worldwide have been immunized during SIAs, demonstrating that well-planned health interventions can reach even the most remote, conflict-affected or poorest areas.
Planning for SIAs provides key demographic data – “finding” children in remote villages and households for the first time, and "mapping" their location for future health services.
In most countries, the Global Polio Eradication Initiative has expanded the capacity to tackle other infectious diseases, such as avian influenza or Ebola, by building effective disease-reporting and surveillance systems, training local epidemiologists and establishing a global laboratory network. This capacity has also been deployed in health emergencies such as the 2010 floods in Pakistan and the 2011 drought in the Horn of Africa.
Routine immunization services have been strengthened by bolstering the cold chain, transport and communications systems for immunization. Improving these services helped to lay the groundwork for highly successful measles vaccination campaigns that have saved millions of young lives.
Vitamin A is often administered during polio SIAs. Since 1988, more than 1.2 million childhood deaths have been prevented through provision of vitamin A during polio SIAs.
On average, one in every 250 people in a country has been involved in polio immunization campaigns. More than 20 million health workers and volunteers have been trained to deliver OPV and vitamin A, fostering a culture of disease prevention.
Through the synchronization of SIAs, many countries have established a new mechanism for coordinating major cross-border health initiatives aimed at reaching all people – a model for regional and international cooperation for health.

Future Benefits of Polio Eradication:
Once polio is eradicated, the world can celebrate the delivery of a major global public good that will benefit all people equally, no matter where they live. Economic modelling has found that the eradication of polio in the next five years would save at least US$ 40-50 billion, mostly in low-income countries.

Last Update : 30 October 2013 02:11 PM
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