The killings, which occurred during a three-day vaccination drive targeting areas of the country hardest hit by the virus, forced the government of Pakistan and the provinces in question to temporarily suspend the campaign due to concerns over the safety of health workers, the United Nations reported on its Web site. Eight volunteers, primarily women, were targeted in Peshawar and the port city of Karachi — two of the regions in Pakistan with the highest rates of polio infection.
With nearly two hundred new cases reported in 2011, Pakistan has the highest rate of polio infection in the world. Immunization drives have proven effective in reducing the number of new victims, and several high-profile donors, including the Bill & Melinda Gates Foundation, have made combating the disease a top priority.
Globally, while setbacks are not uncommon during vaccination drives, this is the first time Pakistan has seen violence of this magnitude against vaccine workers — a development that is being attributed to a number of things, including sectarian and political tensions in the country. For that reason, aid workers, while discouraged, remain committed to the cause.
"This isn't over, not by a long shot," said Sarah Crowe, a spokeswoman for the United Nations Children's Fund. "There's still great energy in the campaign."