We've had no problems with security, and I think that is probably because no one wants to see their babies die. Mostly our teams are welcomed because they know what's going to happen; they're not going to see their babies and their new mothers die.
The other thing is that by using local people to provide the immunization and the education, there's a much greater acceptance. The other thing we've seen is that just like in areas of war where you have raid parties, people doing the vaccinations are also doing raid parties. When the belligerents leave an area, the raid party goes in and provides vaccination.