STEVE INSKEEP, HOST:
Okay. To all the other security concerns in Israel you can now add this. The polio virus is spreading through Israel's sewage system. So far nobody has gotten sick, but Israel has launched a massive emergency immunization drive to revaccinate all children under the age of nine. NPR's Jason Beaubien reports.
JASON BEAUBIEN, BYLINE: The polio virus was first detected in southern Israel in February. Now it's been found in 85 different sewage samples across the country. Chris Maher, a senior advisor on polio eradication at the World Health Organization in Geneva, says there have no reports of Israelis getting sick or paralyzed, in part because Israel has one of the highest rates of polio immunization in the world. But he adds...
CHRIS MAHER: Any time that virus is circulating, if there's anyone who's not immune, there's a risk that that person is going to get clinical polio. They're going to get infected and they're going to get sick. And there's no way that 100 percent of the population can be immune at any given time so there is a risk in Israel itself that we will see clinical cases of polio.
BEAUBIEN: In response, the Israeli government last month launched a rapid vaccination campaign to re-immunize all kids under the age of nine against the disease. The drive aims to give polio boosters to a million children. Israel's last polio case was reported in 1988, and the WHO declared the country polio-free in 1992. Maher says the fact that the virus is being found across a wide geographic area shows that it has re-established a foothold in and it's reproducing in the community.
MAHER: The Israel situation is a significant one because it represents an area of circulation in a world that really doesn't have very much polio anymore.
Last year there were only 223 polio cases anywhere on the planet. And they were in remote areas around Nigeria, Afghanistan and Pakistan. Genetic testing of the samples from Israel show that the virus recently came to the Middle East from Pakistan. Exactly how it got there - boat, plane, truck, bus - is unclear. But it is known is that the virus can travel inside someone's intestines without making that person sick and then escape into a new environment.
Maher says there's concern that polio may now spill out of Israel.
As long as the virus is circulating, it's in people's guts, there is the possibility that the virus can, you know, move to another area where perhaps there's not as much protection as there is in Israel at the moment and where there's a greater opportunity for the virus not only to circulate but also to cause clinical disease.
BEAUBIEN: The current problem in Israel is driven in part by the type of vaccine they use. Israel uses a dead polio vaccine. It's given as a shot and doesn't contain any of the live polio virus. This dead vaccine is the same one that's used in the U.S. and most of the developed world. Most of the developing world uses a live oral polio vaccine. The oral vaccine is administered as a few drops into a child's mouth.
It contains a weakened, although still live, form of the polio virus. The injectable dead vaccine does a great job of protected the individual who is vaccinated, but the person can still carry the virus and pass it on. The oral live vaccine is better at wiping out polio in the entire community. To combat the current situation, Israel is switching over to the oral live vaccine to try to stop the transmission of the virus.
The Palestinian Authority actually uses both the live and dead vaccines in its routine immunization programs. Maher says this may be why the virus hasn't spread into the Palestinian territories. Jason Beaubien, NPR News.