Displaced Syrian children line up to receive polio vaccinations at a refugee camp in the southern port city of Sidon, Lebanon.AP Photo/Mohammed Zaatari
More than 20 million children are set to be vaccinated against polio in Syria and neighboring countries to try stopping the spread of the paralyzing infectious disease following its re-emergence in Syria after 14 years, United Nations agencies said on Friday.
The mass vaccination against polio, which can spread rapidly among children, is already under way in the Middle East a week after the region declared a polio emergency, the World Health Organization (WHO) and UNICEF said.
The threat of the re-emergence of polio is not limited to countries near Syria, a paper released in the Lancet medical journal on Friday said. Two German researchers warned that Syrian refugees fleeing the nearly three-year-old civil war there could introduce polio into Europe, especially in countries with relatively low vaccination coverage like Ukraine and Austria, if more is not done to contain the virus.
The U.N.'s aim to vaccinate about 20 million children in seven countries and territories will be the largest-ever consolidated immunization drive in the Middle East.
"The polio outbreak in Syria is not just a tragedy for children, it is an urgent alarm – and a crucial opportunity to reach all under-immunized children wherever they are," Peter Crowley, UNICEF's chief of polio, said in a news release.
He said the recent outbreak in Syria, confirmed by the WHO last week, should "serve as a stark reminder to countries and communities that polio anywhere is a threat to children everywhere."
WHO spokeswoman Sona Bari said it would take six months of repeated campaigns to reach 22 million children.
"It is going to need quite an intense period of activity to raise the immunity in a region that has really been ravaged both by conflict in some parts, but also by large population movements," she said at a briefing in Geneva.
The first polio outbreak in Syria since 1999 has so far paralyzed 10 children and poses a risk of paralysis to hundreds of thousands of others across the region, the WHO said.
Syria's immunization rates have plummeted from more than 90 percent before the conflict to around 68 percent now.
Preliminary evidence has indicated the virus is of Pakistani origin, but results of genetic sequencing are still awaited. Polio is endemic in Pakistan, along with Nigeria and Afghanistan.
Tracing the source
"We're never going to know how exactly how it arrived in Syria," Bari said.
"We also know that adults tend to have much higher level of immunity already developed, so it is unlikely that adults brought this in. It is more likely some other route."
Children who live in unsanitary conditions are particularly vulnerable to infection with the polio virus, which spreads through fecal-oral transmission, often in contaminated food and water.
It attacks the nerves and can kill or paralyze, often spreading widely and unnoticed before it starts affecting children. There is no cure, but it can be prevented though vaccination.
Emergency immunization campaigns in and around Syria to prevent transmission of polio and other preventable diseases have vaccinated more than 650,000 children in Syria, including 116,000 in the northeast Deir-ez-Zor province where the polio outbreak was confirmed.
The WHO said the vaccinations were vital in a region that had not seen polio for nearly a decade, but which in the last 12 months has detected the polio virus in sewage samples from Egypt, Israel, the West Bank and Gaza Strip.
Dr. Ala Alwan, the World Health Organization regional director for the eastern Mediterranean, said what was needed was "a consolidated and sustained assault" on the disease.
UNICEF said it had procured 1.35 billion doses of oral polio vaccine (OPV) to date in 2013, and by the end of the year will have obtained up to 1.7 billion doses to meet increased demand.
The WHO said the vaccination campaign inside Syria would target 1.6 million children with vaccines against polio, measles, mumps and rubella.
In Jordan more than 18,800 children under the age of five were vaccinated against polio in a campaign in the past few days targeting all children at Zaatari camp, and a nationwide campaign is under way to reach 3.5 million people with polio, measles and rubella.
Europe may be next
Meanwhile, experts warned that refugees fleeing the civil war in Syria could re-introduce polio to Europe. University of Tubingen's Martin Eichner and Stefan Brockmann of Reutlingen Regional Public Health Office said in the Lancet that the polio vaccine used in Europe is not always effective enough to prevent transmission of the virus, and that low vaccination coverage rates in a few European countries leaves countries like Bosnia Herzegovina, Austria and Ukraine particularly vulnerable.
Because only one in 200 polio infections produces symptoms, the virus could be circulating for nearly a year before a single case occurs, according to the German researchers. By then, hundreds of individuals could be carrying the virus.
"Routine screening of sewage for polio virus has not been done in most European countries," they wrote. "But this intensified surveillance measure should be considered for settlements with large numbers of Syrian refugees.”
Al Jazeera and Reuters