Immunization stands at a crossroads after an astounding 15 years of vigorous campaigns around the world. Through determined efforts of national governments, international agencies and hundreds of thousands of volunteers, 2.5 million children’s lives are saved each year. But there are still 30 million infants not protected by routine vaccination in developing countries. They are among the 11 million children who die from preventable causes every year. How to reach these unreached children and extend the power of new or improved vaccines within poor countries are the twin challenges now facing the world.

I can think of no other human endeavour that has as dramatic, deep and positive a legacy as does immunization.

In countless tiny villages and dense urban centres, from Africa and Asia to Latin America and the former Soviet Union, more than 100 million babies a year are immunized, receiving vaccines to prevent diphtheria, tetanus, whooping cough, polio, measles and tuberculosis, saving millions from death and sparing millions more at minimal cost from paralysis, visual impairment and brain damage.

Generations of healthy adults owe their very lives to the fact that they were immunized as children and protected against life-threatening diseases. And the material and human progress so many societies have made rests heavily on public health improvements, of which immunization is a linchpin.

Yet immunization’s success is a low-key, quiet and self-effacing story taken for granted by many, especially in the industrialized world, where it is still saving lives. It does not receive the attention and acclaim it deserves even in the developing world, where its contribution, particularly over the past 15 years, has been truly remarkable. Since the 1970s, global coverage has soared from less than 10 per cent to almost 75 per cent, saving the lives of 2.5 million children each year.

Not since the eradication of smallpox over 20 years ago has the power of immunization been so evident as in the stunning success of the 12-year campaign to eradicate polio. The world has watched and applauded as immunization efforts have pushed back the wave of disability, suffering and death brought on by polio. Polio cases, which reached an estimated 350,000 a year as recently as 1988, had dropped to about 7,000 by 1999.

In a global mobilization unmatched in peacetime, 470 million children under five years of age were immunized in 1999, an extraordinary achievement made possible by the selfless, committed and sustained efforts of Rotary International, UNICEF, WHO and more than 10 million volunteers in nearly 100 nations.

The efforts have been well rewarded. North and South America have officially been certified polio-free, and in Europe only Turkey reported a few cases in 1998. The disease is rapidly disappearing from most of eastern and southern Africa, North Africa and the Arabian Peninsula. In East Asia and the Pacific, the last indigenous case was reported in Cambodia in 1997. Polio has now retreated to outposts in Afghanistan, Bangladesh, India, Nepal and Pakistan in Asia, and Somalia, Sudan and parts of West and Central Africa, where it clings on partly because of wars, poverty and difficulties in reaching some areas. But the world is determined to prevail against polio.

* Dr. William Foege is Presidential Distinguished Professor of International Health of the Rollins School of Public Health, at Emory University in Atlanta, Georgia. He is a Senior Adviser for the Bill and Melinda Gates Foundation and Principal Investigator on Grants awarded to the Task Force for Child Survival and Development. See profile.