Some of my patients have asked this question over the last four weeks. The answer is: We won't know for another couple of months. So far the 2011-12 flu season has claimed about three lives, according to reports received by the Centers for Disease Control (CDC). Compared to the previous flu season (2010-11) hospitalizations and deaths are dramatically down. Does this mean it is time to rejoice? Is the pressure off of those who have put off getting their flu vaccine for this year?
The answer to both of the above questions is "No". Reports from the CDC have shown an increase in flu illnesses over the last two weeks. The first percentage increase was from about 7 percent (incidence of respiratory secretions positive for flu virus) to 10 percent nationwide as of Feb 4th. This indicator jumped to 15 percent on the week ending Feb 11th. What does this mean? The CDC reports this as being one of the latest starts for flu season going back several decades. California and Colorado report widespread activity. Many other states have increased reports of flu activity.
No, now is not the time for complacency and neglect. You or your child should get flu vaccination in order to best prepare for this year's flu season. If you are one of those who have not yet been vaccinated consider yourself lucky to have not yet been exposed. The tardiness of widespread flu activity in 48 of America's states is a stroke of luck for millions of people. This allows them more time to get vaccinated before the flu spreads to regions in which they reside.
Why Such a Late Seasonal Surge in the Flu?
Nobody knows for sure. A combination of climate changes, activity/travel of people and animal exposure appear to have a lot to do with each flu season and epidemics that arise. These variables are very unpredictable. Scientists are still searching for ways to predict potentially bad flu seasons but the pesky flu virus particle which has the ability to mutate as it passes through various animal and human hosts complicates their efforts. Of course, successful flu vaccination of the U.S. population may contribute to lower flu related illnesses and mortality but annual reports show that many adults (about 40 percent) remain unvaccinated.
Death rates from flu syndrome in the U.S. annually range between 3000 and 50,000. If flu season 2011-12 is just getting started many people still have a chance to protect themselves by getting vaccinated. It takes two weeks to mount a protective antibody response, which may be adequate for many people across the nation where flu is not widespread.
The CDC has new provisions on how to approach people who are egg allergic and desire flu vaccination. Recent studies have reported low risk of anaphylaxis if the egg allergic reaction was not severe (involving throat closure or shock).The new recommendations mean fewer egg allergic people will require skin testing to the flu vaccine and/or fractionated flu vaccine injections (flu shot divided into a series of two to three injections).