NEW YORK — The flu vaccine did a poor job protecting older Americans against the illness last winter, even though the vaccine was well-matched to the flu bugs going around.U.S. health officials on Wednesday released new vaccine data showing it did a so-so job overall.The vaccine was about 42 percent effective in preventing illness severe enough to send a patient to the doctor's office. But it was essentially ineffective protecting some age groups. That includes people 65 and older — the group that's hardest hit by flu, suffering the most deaths and hospitalizations.The flu season that just ended was a long one that peaked in February and was considered moderately severe.