Studies show flu vaccine is less than 40% effective

Studies show the flu vaccine is doing a poor job protecting older generations and others against the strain that is causing most illnesses.

The preliminary numbers suggest the vaccine is 36% effective overall in preventing flu illnesses severe enough to send a patient to the doctor’s office.

Officials said there has only been one time in the last decade when the flu vaccine did a worse job.

Most illnesses this winter have been caused by the strain Type A H3N2. The vaccine was only 25% effective against that type.

Experts said the vaccine’s poor performance is one reason why the United States has been suffering an intense flu season.