Despite a worldwide effort to eradicate polio (poliomyelitis) — in 2013 there were only three countries where it was endemic — the Middle East is gearing up this month to vaccinate as many as 10 million children, regardless of whether they previously got it, after the crippling disease reappeared in Syria last year.

“Polio does not respect borders,” said Ala Alwan, World Health Organization regional director for the eastern Mediterranean, according to AFP. “The detection of polio in Syria is not Syria’s problem alone, but one requiring a regional response. The safety of children across the Middle East relies on us being able to put a stop to polio in Syria.”

In all, seven countries across the Middle East are planning to vaccinate children, UNICEF said. Campaigns began on Sunday in Egypt, Iraq, Jordan, and Syria, while they are expected to begin vaccinations in Lebanon on March 9. The coordinated effort from the World Health Organization comes after not only the Syria outbreak but also after polio samples were found in sewage in Egypt, Israel, the West Bank, and Gaza Strip. All of them are suspected to have come from Pakistan, one of the last countries still plagued by polio.

“To vaccinate so many children in different countries is a huge undertaking,” said Maria Calivis, UNICEF regional director for the Mideast and North Africa, according to AFP. “Each country faces its own set of challenges in order to make the campaign effective — above all in Syria — but this is the only way we can ensure children across the region are properly protected against this terrible disease.”

The highly-infectious disease typically infects a person’s throat and intestines — most often infecting children under 5 years old. Although almost 72 percent of those infected don’t feel symptoms, 24 percent feel relatively minor symptoms, including fever, fatigue, nausea, and stiffness in the neck and back. The disease’s danger comes from its ability to cripple the nervous system, causing one in 200 people to become permanently paralyzed, most often in the legs, which causes death in five to 10 percent of them when the paralysis hits the respiratory muscles.

The Origins of the Polio Outbreak

The outbreak first appeared in Syria in October, when a group of people living in Syria’s Deir ez-Zor province were found to have unconfirmed acute flaccid paralysis, which is a symptom of polio, characterized by the sudden onset of weakness in a person’s extremities. With political strife and civil war, some territories, such as Deir ez-Zor, stopped maintaining sanitation and safe-water services, and began denying immunizations for preventable childhood diseases. As of Dec. 17, there were 24 cases of polio in Syria. However, the number of infected persons could be much higher. Since conflict began in 2010, roughly 1.8 million children were born, with the possibility that more than half are unvaccinated, The New York Review of Books reported.

Nevertheless, health teams are dedicated to preventing the virus from spreading further. “We need to get two drops of polio vaccine into the mouth of every child under the age of 5, regardless of their previous immunization history,” medical worker Khouzama al-Rasheed said, according to UNICEF. “If we can do that, the virus won’t be able to find a single child to infect, and we can put a stop to this disease.”