2007-2008 Flu Season Worse Than Usual

Although it always seems like the current year’s flu season is always worse than the last, this year it may actually be true.  According to the Centers for Disease Control and Prevention (CDC), the 2007-08 flu season peaked in February 2008.  However, there are growing concerns of the continuing rate of flu infections after the peak of flu season.  Another concern is the rate of death related to flu and pneumonia this season, peaking at 9.1%; a rate higher than 6.9% is an epidemic level.  This rate has exceeded epidemic levels for 13 straight weeks.

At it’s peak, flu illness accounted for nearly 6% of all doctor visits in February 2008.  Making matters worse is the flu vaccine has only been 44% effective this season.  This is because the flu virus responsible for causing the majority of illness this season was not included in the vaccine.  Although there was a similar viral strain included in the vaccine, it is not identical, and therefore less effective.  Flu vaccine manufacturers have to choose in February what viral strains to include in a vaccine that won’t be distributed until the fall.  It is not clear what strain may become dominant that far away from flu season, resulting in situations every season where a single strain of influenza can wreck havoc.

Although this flu season has been worse than usual, it is useful to keep this in perspective.  The 1918-1919 flu season killed between 30-50 million people worldwide, with Americans accounting for approximately 675,000 deaths.  This was more than the number of people who died in World War I.  We may be in for a bumpy road this flu season, but it does not appear to be anywhere near as bad the flu pandemic of the 20th century.