In years like this one, when the flu vaccine was at best minimally effective, many are skeptical about getting the shots, which are widely available. Dr. Monto said there are efforts underway to produce much better flu vaccines. But, he said, because Congress is not very interested in seasonal flu, the National Institutes of Health had to tie requests for funds for flu vaccine research to pandemic preparedness.

Historians say a nonchalance about flu dates back to at least the 19th century.

Nancy Bristow, chair of the history department at the University of Puget Sound, looked at newspaper articles and other sources from the end of the 19th century and into the 20th century and found “a perennial refusal to pay attention to flu as a serious illness.”

Flu was not frightening, Dr. Bristow said, “because it was so familiar.” It was not even a reportable disease until the 1918 pandemic.

People made light of the flu in advertisements. One published in the Atlanta Constitution in 1890 said: “Kerchew! Achew!-Hew!!! Most every one has the Grippe in some form, and we would like to get Our Grip on your purchase of Furniture, Carpets, Mantels, Etc.” (Flu was once referred to as Grip or Grippe — the French word for influenza.)

An ad from the Golden Eagle Clothing Company suggested a “doctor’s prescription” for a “poorly-clad boy” who “was suffering from la grippe,” writing, “The doctor has influenz-ed his mother to purchase one of those $2.50 all wool boys’ suits.”

Occasionally, public health officials issued warnings. One that Dr. Bristow found was published in 1916 in the Journal of the American Medical Association. It said: “Don’t laugh at the grip. It is a deadly and dangerous thing.”

The laughter stopped in 1918, when a new influenza strain caused a pandemic with a frightening mortality rate. But when that pandemic ended, Dr. Bristow said, complacency resumed. People wanted to put that awful period behind them.