Flu Vaccines Not As Effective This Year According to the CDC

Did you get a flu shot this year? And if so, did it truly protect you against the flu? I didn’t get the flu shot this year, and so far I haven’t come down with the flu. And now, it looks like I actually may have saved myself some money by not getting the shot. Why is that? Well, the U.S. Centers for Disease Control and Prevention (CDC) state that this year’s seasonal flu vaccine has only been effective 44 percent. Only 44 percent? Can that be right? Let’s take a closer look . . .

Flu Shot Findings
The percentage comes from the CDC’s study, the findings of which are published in this week’s issue of the federal agency’s April 17, 2008 Morbidity and Mortality Weekly Report (MMWR).

The figure comes from overall vaccine effectiveness for influenza Type-A (H3N2), and the influenza type B. Type A is what makes up the majority of the strains so far this year.

The type A flu shot has been confirmed to be 58% effective, but type B was zero percent effective.  Therefore, it’s been shown that the vaccine offers no protection against the type B strain.

This study was from the CDC Marshfield clinic in Wisconsin that included patients from January 21 to February 8, 2008, that lived in or around Marshfield, Wisconsin.  The results were shared in a recent web conference by Dr. Dan Jernigan, Deputy Director, CDC Influenza Division, National Center for Immunization and Respiratory Diseases (NCIRD).

Dr. Jernigan said that most of the flu viruses circulating this year have been "less than optimally matched to the viruses in the vaccine." He said the main strains circulating this year were type A H3N2, type A H1N1, and type B. He said that type A H3N2 constituted the majority of the strains circulating this year, and within those, 70 percent were a series of strains called A-Brisbane10/2007."

Jernigan said that while the Brisbane strain had "drifted," it was still "somewhat related" to A-Wisconsin strain, which is in this year's vaccine. Of the type B, over 90 percent are of the B-Florida strain, which belongs to the Yamagada lineage, and which is quite different from the Victoria lineage that is in this year's flu vaccine.”

What does this study mean?
This 44 percent figure means that the people who were included in the study were 44 percent less likely to have laboratory diagnosed influenza than those in the study who did not receive the flu shot.  Although it doesn’t seem to be a very reassuring statistic, this number is high enough to justify continuing to promote getting the vaccination.
However, Jernigan pointed out that because of the less than optimal level of protection this year, health professionals should consider using the “three pronged approach” to protect against the flu in the future.

This approach consists of getting vaccinated, taking everyday precautions such as covering your cough or washing your hands so that germs don’t spread, and taking an anti-viral drug.

The study mentioned in the MMWR report was based on laboratory data.  Jernigan said that the CDC was beginning to get early figures, but still continues to promote flu shots.

This year, a record number of Americans were vaccinated against the flu.   There were around 113 million doses of flu vaccine delivered by drug companies in the U.S. this year alone.  This is more than ever before, around ten million more doses than last year.

At the peak of the season of this year, around the middle of February, deaths from the flu peaked to reach 9.1 percent of all deaths in the U.S.  This is similar to 2003-2004 when the death rate was 10.4 percent of all U.S. deaths.

In the U.S. this year, Connecticut, Maine, Maryland, New York, Pennsylvania and Vermont all experienced an epidemic of widespread infection of the flu.

And so . . .
Despite these findings, it looks like getting the flu shot is still a viable option in protecting yourself. However, it brings up a valid question: could we be trending to a situation where flu vaccines become less and less effective each year – similar to certain infections that are becoming resistant to antibiotics? And if so, what will that mean for your future health? Something to think about.