Federal health officials say fewer than half the Americans who most need a flu shot get one. That includes those most at risk from life-threatening complications, including babies, toddlers and the elderly.
Despite worries about the availability of vaccines, an expert at the Centers for Disease Control says a record 100 million doses will be available this year. He says that means the big challenge now is persuading people to get their injections.
Several months ago, one big supplier sparked worries about the vaccine supply when it was forced to delay its shipments, for fear of contamination, but the CDC official says those concerns affected only a small amount of Chiron Corporation's vaccine and the rest appears to be fine.
The vaccines will be shipped to doctors' offices in late October.