Scientists say it isn't clear whether the drug will work for all groups at high risk of infection because the virus enters the body in different ways in each case.

WSJ: Daily Pill Slashes Risk of HIV Infection in Study

This is especially the case because for all the attention that the 2011 strategy has received, it is in many ways less complete when it comes to addressing these questions than the 2006 strategy.

FORBES: DOD's "First" Cyber Strategy is Neither First, Nor a Strategy