Via Conflict Health, The Guardian reports that the "CIA organised fake vaccination drive to get Osama bin Laden's family DNA":
In March health workers administered the vaccine in a poor neighborhood on the edge of Abbottabad called Nawa Sher. The hepatitis B vaccine is usually given in three doses, the second a month after the first. But in April, instead of administering the second dose in Nawa Sher, the doctor returned to Abbottabad and moved the nurses on to Bilal Town, the suburb where Bin Laden lived.
Christopher Albon of Conflict Health writes:
If true, the CIA’s actions are irresponsible and utterly reprehensible. The quote above implies that the patients never received their second or third doses of the hepatitis B vaccine. And even if they did, there is absolutely no guarantee that the vaccines were real. The simple fact is that the health of the children of Abbottabad has been put at risk through a deceptive medical operations by the Central Intelligence Agency. Furthermore, the operation undermines future vaccination campaigns and Pakistani health workers by fueling conspiracy theories about their true purpose.
Albon notes that the Guardian's source is Pakistan's ISI... but this McClatchy story seems to confirm it via US sources:
The doctor's role was to help American officials know with certainty that bin Laden was in the compound, according to security officials and residents here, all of whom spoke only on the condition of anonymity because they feared government retribution. U.S. officials in Washington confirmed the general outlines of the effort. They asked not to be identified because of the sensitivity of the topic.