Millions of Americans have given up on getting flu shots this year, frightened off by news reports of long lines or discouraged by their own failed attempts, U.S. health officials said on Thursday.

But the Centers for Disease Control and Prevention said there were still enough flu vaccine doses left for people who really need them and urged the elderly and other priority groups to get the shots.

There is still time because the influenza season, which peaks in February, is off to a slow start and vaccines are still being distributed, said CDC head Dr. Julie Gerberding.

“Early in the season when there were long lines, people did get discouraged,” Gerberding told a news conference.

This year’s vaccine supply was disrupted when one of two major makers, California’s Chiron Corp., lost the license at its British manufacturing plant because of bacterial contamination and had to scrap 48 million doses.

That left the other manufacturers to try and make up as much of the gap as possible. Aventis has supplied most of the remaining 61 million doses that will be available, and the U.S. government has arranged to buy several million more doses from GlaxoSmithKline’s German supply, as needed.

The CDC estimates that 185 million Americans are either in the higher risk categories - over the age of 50, under the age of two, pregnant or having a chronic condition such as diabetes or the AIDS virus - or healthcare workers or caregivers who need to protect contacts from flu.

LACK OF DEMAND

But many people who should get vaccinated fail to do so, and this year the CDC predicted that up to 50 million Americans who fall into the recommended category are expected to seek the vaccine.

The CDC and Harvard University researchers surveyed Americans and found that 63 percent of seniors and 46 percent of adults with chronic illnesses who tried to get the shot were able to. Half of those eligible did not try.

Gerberding said she was pleased with