These six groups are nursing home residents, people with chronic medical conditions like asthma, the elderly, pregnant women, health care workers, and children from ages 6 months to 2 years, Butler said.

CNN: Flu vaccine attitudes abroad differ from U.S.

In some of these states, there are four, five, six of these groups up at a time.

WHITEHOUSE: Press Briefing

We would need more evidence that more than these six key, target high-risk groups that are prioritized can benefit.

CNN: Flu vaccine attitudes abroad differ from U.S.