This may help identify a new high-risk group, she says.

Young adults aged 17 to 20 are also a high-risk group.

Military and other high-risk groups continue to get the vaccine.

Still, she said, many more people should get the shot, especially those in high-risk groups.

"Many high-risk groups are no longer concentrated in the city," he said.

The smart place to battle it is among the high-risk groups.

Generally, their premiums are far lower than those in the high-risk group.

Can a supplement hurt if you are not in one of those "high-risk" groups?

The plan is to provide vaccines only to those in high-risk groups and to medical workers.

When members of high-risk groups are tested, the false positive rate is much lower, but still significant.