Polio endemic countries hit all-time low of four

Eradication drive enters new phase with global roll-out of monovalent vaccines.

1 FEBRUARY 2006 | GENEVA/EVANSTON/ATLANTA/NEW YORK -- The number of countries with indigenous polio has dropped to an all-time low of four, as polio eradication efforts enter a new phase involving the use of next-generation vaccines targeted at the two surviving strains of virus.

In 2006, monovalent vaccines, aimed at individual virus strains, will be the primary platform for eradication in all remaining polio-affected areas, announced the core partners in polio eradication – the World Health Organization (WHO), Rotary International, the US Centers for Disease Control (CDC) and Prevention and UNICEF – enabling the eradication drive to hone in on poliovirus types 1 and 3.

This new phase was announced alongside the confirmation that indigenous poliovirus has not circulated in Egypt and Niger for over 12 months. This is the first time in three years that the number of polio-endemic countries has fallen, leaving Nigeria, India, Pakistan and Afghanistan as the only countries that have never stopped indigenous polio transmission.

“Polio has been endemic in our country for all of recorded history,” said Egyptian Minister of Health Dr. Hatem Mostafa El-Gabaly. “The best tools of our age finally defeated this enemy who has been with us from pharaonic times.” Monovalent vaccine targeted at the type-1 poliovirus circulating in Egypt was used during vaccination campaigns there in May 2005.

Unlike Egypt – where the challenge to eradication was highly efficient polio transmission in crowded cities – Niger faced a sparse population, some of it nomadic, scattered over a vast country with a heavily-travelled border with Nigeria, the world’s largest reservoir of poliovirus. Multiple immunization campaigns in Niger were painstakingly planned to ensure children were being vaccinated even in the remotest and border areas. In 2005, the nine polio cases reported in Niger were all the result of importations over this border.

The success in Niger and Egypt is the result of intense efforts in 2004-05 to halt Africa’s polio epidemic and fast-track the introduction of monovalent polio vaccines into selected areas. The number of cases of polio in India and Pakistan in the last quarter of 2005 also fell by more than half compared with the previous year, due to more effective immunization strategies and the use of monovalent vaccine.

"To fully exploit these new tools, government commitment in Nigeria must remain high at all levels to ensure that all children are vaccinated,” said Jonathan Majiyagbe of Kano, Nigeria and past President of Rotary International, which has contributed more than US$ 600 million and countless volunteer hours to a polio-free world. Ninety per cent of polio cases in Nigeria are concentrated in just eight of the country’s 37 states.

In addition to mass immunization with monovalent vaccines in the four endemic countries, large-scale campaigns with these vaccines will need to take place in 2006 in eight countries – including Somalia, Indonesia and Yemen – to stop recently imported polioviruses. Critical to the success of these campaigns is a US$ 150 million shortfall which must be filled as rapidly as possible. The eradication effort requires a further US$ 425 million for the 2007-2008 period.

Notes to editors

The Global Polio Eradication Initiative is spearheaded by national governments, the World Health Organization (WHO), Rotary International, the US Centers for Disease Control and Prevention (CDC) and UNICEF.

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 Russian Federation, Saudi Arabia, Spain, Sweden, 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 corporate partners (e.g. Sanofi Pasteur, De Beers, Wyeth). Volunteers in developing countries also play a key role; 20 million have participated in mass immunization campaigns.

Circulation of wild poliovirus: Between 1988 and 2004, global eradication efforts reduced the number of polio cases from 350 000 annually to a low of 1189 cases. In 2005, the number of cases rose again to 1831 (as of 17 January 2006), at the peak of the epidemic originating in northern Nigeria and infecting 21 previously polio-free countries between 2003 and 2005.

The last wild poliovirus reported in Egypt was found in an environmental sample on 13 January 2005. All nine cases of polio recorded in Niger in 2005 were the result of importations from Nigeria. Four countries remain polio endemic: Nigeria, India, Pakistan and Afghanistan. Eight countries have reported circulation of imported poliovirus in the past six months: Angola, Chad, Ethiopia, Indonesia, Nepal, Niger, Somalia and Yemen.

Types of poliovirus: Polio is caused by poliovirus type-1, type-2 or type-3. Type-2 poliovirus has been eliminated. Monovalent oral polio vaccines (OPV) – targeted at poliovirus types 1 or 3 – appear to work faster than traditional trivalent OPV to build immunity against these specific polio types. Used for the first time in the eradication initiative during 2005, monovalent OPV appears to have stopped transmission in Egypt and parts of India.

Contact Information

Linda Venczel

CDC/Atlanta

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