Deployment of chemical weapons in Syria has proven to be such a horrific event, it has mobilized the muscle and diplomacy of the most powerful international actors. What will it take to unleash this same determination to come to the aid of the youngest Syrians?

Prior to the onset of the civil war, Syrian children as a group were reasonably healthy. Neonatal and infant-child mortality were fairly low, comparable to countries such as Brazil or Turkey. Syrian public health indicators were consistent with a high-functioning health system: 88% of women received antenatal care, 96% delivered their babies attended by a skilled healthcare professional. More than 80% of children were immunized with a dose of measles vaccine and 3 doses of a 3-in-one that covers diphtheria, tetanus, whooping cough, plus the Hemophilus B vaccine that protects against a common cause of pneumonia and meningitis. Polio had been absent from the country since 1999, the result of more than 80% of children receiving 3 doses of the oral drops before age 2.

Well over 100,000 people have succumbed to this conflict from blast injuries, burns or gun shots. But others also died, or are permanently disabled, because of preventable illnesses that many Syrian families had come to believe were relegated to the past. The resurgence of polio is just the latest, most visible example - backed by a determined, well-resourced political movement that seeks its eradication. But if polio is back, measles is already there. A measles epidemic broke out in northern regions of Syria in early 2013 with more than 7,000 cases. Médecins Sans Frontières has vaccinated more than 75,000 children against measles this year. Whooping cough, or even diphtheria, may not be far behind. Healthcare professionals in Syria would be wise to brush up on the clinical presentation and management of diphtheria - a deadly disease most have probably never encountered. This is occurring because vaccination rates have been cut in half for Syria's young children over the past 2 years; the drop is certainly more precipitous in regions outside of government control.

UNICEF's Executive Director Anthony Lake has traveled to Damascus to highlight the launch of a Ministry of Health led vaccination campaign "where possible, given security and capacity constraints." Tellingly, he is in Damascus not in Deir-ez-Zour Province, the area in north east Syria where the polio cases have been confirmed. Just as with the measles epidemic, it is primarily the children in northern Syria who are under siege by these preventable infectious diseases.

Immunizations are a basic and, as events in Syria demonstrate, essential feature of healthcare for children in the 21st century. Although Director Lake asserts vaccines should not be seen as a political act, the reality is that the conditions necessary for vaccinating children require significant political will. Catch-up immunization on the scale now required for Syrian children means organizing campaigns, establishing corridors of safe passage for health care personnel and materiel in all regions of the country and negotiating with all actors to guarantee security for those involved - most notably children in line awaiting immunization.

If it turns out that 20 children paralyzed by polio and threat of a wider epidemic is able to force humanitarian access where more than 100,000 deaths or 7,000 children with measles could not, then the Global Polio Eradication Initiative may mark one of its most life-saving accomplishments.