Flu reaches epidemic level in U.S., says CDC
While flu vaccines offer protection, they are not failsafe.
This year's flu vaccine is 62 percent effective, scientists reported on Friday in the CDC's weekly publication, meaning that almost four in 10 people who receive the vaccine and are exposed to the virus will nevertheless become infected.
This is considered "moderate" effectiveness and is in line with previous years' flu vaccines, which range from 50 percent to 70 percent effective, Dr. Joseph Bresee, chief of the CDC's influenza division.
Dr. Arnold Monto of the University of Michigan, a co-author of the vaccine-effectiveness study told Reuters this year's vaccine was "a good vaccine, but not a great vaccine."
NOTE**************************
It is less effective for the frail elderly, for people receiving chemotherapy for cancer, and for people taking oral steroids, as their immune systems have been weakened and are often unable to produce an effective number of antibodies in response to the vaccine.
*********************************