Thousands of Syrians still cross into neighboring countries every day, at least half of them are children. NPR's Deborah Amos reports from Beirut.
DEBORAH AMOS, BYLINE: In this refugee camp in eastern Lebanon, aid workers put sandbags around plastic tents to keep winter rains from flooding dirt floors. For weeks now, the threat for refugees was the coming cold. Now a bigger fear is polio. Lebanon hasn't had an outbreak in 12 years. The announcement of 10 confirmed cases in Eastern Syria was a wake-up call for the region, says Dr. Foaud Foaud. He's a professor of health services at American University, and says it requires a regional response by health workers and aid agencies.
DR. FOAUD FOAUD: I think it's not about just fast enough. They should be wide enough. They have to reach, you know, now, you know, five countries.
AMOS: How easy is that to do in time?
FOAUD: It's not easy at all. It's very difficult. But it's a must now.
AMOS: A must, he says, as Syrian refugees stream into neighboring Turkey, Iraq, Jordan and Lebanon. Here in Lebanon, health officials are sending out 5,000 workers for door-to-door immunizations. This weekend the center opens at the airport and at the border to immunize young children as they arrive. In Syria, the government launched an immunization campaign as soon as the first polio cases were reported.
JULIETTE TOUMA: I'm Juliette Touma. I'm the regional spokesperson for UNICEF.
AMOS: UNICEF, the United Nation's children fund, is a key agency supporting the program. UNICEF organized a vaccine airlift that arrived in Beirut and will be trucked into Syria. One immediate focus is in the east, Deir Ezzor, where the outbreak was first reported.
TOUMA: In the past few days, we managed to reach at UNICEF with partners more than 40,000 children in Deir Ezzor where the polio cases have been confirmed. This is only the beginning.
AMOS: The goal, says Touma, is to reach 1.6 million children across Syria, an enormous challenge in wartime. To reach the most vulnerable, aid agencies have to negotiate not just with the government but with rebel groups to allow them to work in areas they hold or surround.
TOUMA: The challenges are huge. Our staff have to cross sometimes over 50 checkpoints. It's a huge risk to reach people in need.
AMOS: Rebels present another challenge. Some are foreign fighters. There are strong suspicious that the virus that infected Syrian children could have come from Pakistan, says Dr. Foaud, a tragedy, he says. Polio was eradicated in Syria 14 years ago, the first country in the Arab world to introduce mass immunization.
FOAUD: We're facing now strange people fighting in Syria. We're seeing strange diseases that we thought were finished. It means now, it's a collapsed system. So, no one wants to say it's a failed state, but at least in some part, it is, it is.
AMOS: Now a regional health threat, the Syrian government is already under pressure to open humanitarian corridors and allow cross-border aid. That pressure will get much stronger. Deborah Amos, NPR News, Beirut.