Recent experiences with highly pathogenic H5N1 avian influenza have given the world its first advance warning that another influenza pandemic may be imminent.
Given the serious consequences of past pandemics, this advance warning has stimulated a search for ways to prevent such an event from occurring through preparedness, rapid response and containment.
Stop or slow the spread
The rapid response and containment strategy aims to stop, or at least slow the spread of pandemic influenza at the source of its emergence in order to minimize global morbidity and mortality.
In the event that this strategy fails to contain a pandemic, it will at the very least delay the spread of the virus and buy time to allow for vaccine development and production, antiviral manufacture and transport as well as other pandemic preparedness measures.
No attempt has ever been made to alter the natural course of a pandemic near its start.
Moreover, given the unpredictable behaviour of influenza viruses, no one can know in advance whether the start of a pandemic will begin gradually, following the emergence of a virus not yet fully adapted to humans, or be announced by a sudden explosion of cases, thereby precluding any attempt at containment.