Drug News
Survey: flu shots less effective for the past winter
By Sue Mueller
May 11, 2008 - 9:36:44 AM

SATURDAY May 11, 2008 (foodconsumer.org) -- A new survey by Harris Interactive confirmed an early finding by the centers for Disease Control and Prevention (CDC) that the vaccine used to prevent the flu this past winter was less effective than the flu vaccines used in the previous winters.

The CDC early said that the flu vaccine for the past winter was about 44% effective.   This Harris Poll showed that in this past winter people who received flu vaccine were just as likely to get the flu as those who did not.

Harris Poll found in three previous winters people receiving flu vaccine were 33, 43 and 24 percent less likely to get the flu than people who did not get flu shots.

Harris Interactive gave a couple of reasons to explain why the poll results understated the effectiveness of flu shots for this past winter.   One reason is that it said the straight comparison of the incidence of flu of those who did and did not receive flu shots is not a solid measure of the vaccine's effectiveness because those who got the flu may also be more likely to have flu shots.

Another reason for the low estimate of the effectiveness of the vaccine is that it is difficult for patients and physicians to make a certain diagnosis of flu and its symptoms are similar to that of other conditions.

The message of the survey is, the effectiveness of the flu vaccine for the past winter was not as good as the flu vaccine used for previous winters, which was acknowledged by the government.