Globally, in developed as well as in developing countries, child mortality is on the decline and life expectancy on the rise. In 1960, 182 of every 1,000 children born died before turning five; today, that number is down to 43. A child born in 1960 could expect to live an average of just 52 years; by contrast, a child born this year can expect to live to 71.

Then as now, the factors most likely to determine a child's fate are set at birth: where he or she is born, the educational and economic condition of the family, the availability of medical care. Yet one of the most important advances in public health has reached every country and must now reach every child: immunization.

The use of vaccines has, in many parts of the world, nearly eliminated diseases that once were widespread, such as diphtheria, tetanus, and rubella. Thanks to vaccines, 20 million lives have been saved from measles since 2000. Smallpox has been eradicated – and polio is next.

Thirty years ago, there were an estimated 350,000 cases of polio per year worldwide. As this issue of The Rotarian went to press, only 37 cases of polio had been recorded in 2016 – the lowest number in history. All of the other cases, and the paralysis and death they would have brought, were prevented through the widespread use of a safe, reliable, and inexpensive vaccine.

Overall, the World Health Organization estimates that immunization prevents an estimated 2 million to 3 million deaths every year. It also averts a tremendous burden of disability and economic loss. Yet we could be doing so much better: An additional 1.5 million deaths could be avoided by improving vaccine coverage worldwide.

This month, from 24 to 30 April, we join WHO, UNICEF, and the U.S. Centers for Disease Control and Prevention in celebrating World Immunization Week, raising awareness of the incredible impact that vaccines have had on global health. This year's theme is "Vaccines Work" – and they do. Increased use of vaccines has broader repercussions for public health: controlling viral hepatitis, reducing both the need for antibiotics and the development of antibiotic-resistant microbes, and reaching more children and adolescents with essential health interventions. In every part of the world, routine immunization is as crucial as ever to ensure that all children have the best chance at a healthy future.

In an uncertain world, vaccines offer something remarkable: a way to protect our children throughout their lives. By working together to safeguard all children against polio and other preventable diseases, Rotary is truly Serving Humanity – now and for generations to come.