Looking back on the annals of history, influenza pandemics have happened on average four times a century. The 20th century brought three notable outbreaks: The infamous 1918-9 Spanish influenza and the 1957-1958 and 1968-1967 outbreaks. Many influenza experts agree a fourth pandemic was averted in 1997 when H5N1 first reared its ugly head; Hong Kong responded in 1997 by promptly culling all of its infected poultry. But has the outbreak only been postponed? Some experts believe the arrival of a strain of humanly transmissible H5N1 is imminent. However, as someone else posted earlier, H5N1 vaccines are being manufactured -- and many countries are taking measures to prevent the worst case scenario in the event of an outbreak. Preparedness will also include improved surveillance systems and procedures in place to contain the spread of the virus. Let's just hope we're ready when this thing strikes -- especially developing nations which will be hit hardest.