Close up image of a caretaker helping older woman walk

Influenza hit most of the United States by early January, government officials said.

‘‘This is the first year we have had the entire continental US be the same color on the graph, meaning there is widespread activity in all of the continental US at this point,” said Dan Jernigan, director of the influenza division at the national Center for Immunization and Respiratory Diseases.

The highest hospitalization rates were among those over age 65. A strain of influenza A called H3N2 was causing most of the illness, the Centers for Disease Control and Prevention said.

The flu season lasts into the spring. A new AARP and University of Michigan survey found close to three-quarters of respondents said all staff in long-term care facilities should be required to receive the vaccine. If one-third or more of a facility’s staff weren’t vaccinated, 40% of those polled said they’d be “much less” likely to choose it for them- selves or loved ones. Another third of respondents said that fact would make them “slightly less” likely to choose it.

But creating mandatory flu vaccination policies in healthcare settings has created controversy and even led to firings in some locations.