As this year's flu season approaches, federal and local authorities say they are concerned that the number of people who get vaccinated against the virus has stagnated in recent years.
Though most people recover after a miserable week or so at home, influenza kills thousands of people every year, some of them young and healthy.
"This can be a lot worse than a few days of missed school or work," Dr. Tom Price, U.S. secretary of health and human services, said during a news conference Thursday. "This is a serious respiratory infection that can lead to hospitalization and death."
Price said only 46.8 percent of Americans were vaccinated during the last flu season, and that percentage has changed little in recent years.
Those ages 6 months to 23 months had the highest vaccination rate last season, at 76 percent, but the numbers then drop considerably for other age groups. Seniors, by far the most vulnerable group, had the next highest rate of vaccination, at 65 percent. Only about a third of those ages 18-49 are vaccinated, the lowest rate.
Price and experts from the U.S. Centers for Disease Control and Prevention couldn't say if the coming season would be especially bad, because the virus is unpredictable, but in the Southern Hemisphere, the flu has been rampant this season. Australia has reported a far higher number of cases than normal.
The flu vaccine developed here is based on what happens in the Southern Hemisphere, said the officials, adding that they believe the vaccine is a good match for the season, which typically ramps up in October and runs through at least March.
That could be life-saving, particularly for those 65 and older, who make up 85 percent of the flu-related deaths ever year, said Dr. Kathleen M. Neuzil, director of the University of Maryland School of Medicine's Center for Vaccine Development.
She emphasized that the virus can be deadly at any age but said older adults tend to have chronic health conditions that make them more susceptible to deadly complications like pneumonia.
"This year, I'd like to see a real increase" in vaccinations, she said.
There can be complications from the vaccine, though contrary to myth, it does not cause the flu. The vaccine also isn't 100 percent protective, the experts said, with about a 40 percent to 60 percent rate of efficacy. It take about two weeks for the flu vaccine to start working, they said.
Neuzil said the immune system can begin to decline at age 50, and there are two vaccines developed in recent years specifically for seniors — one that is four times stronger than regular vaccines and another with a so-called adjuvant that boosts the vaccine's power. She said those unsure which vaccine to get should consult a doctor.
All vaccines are shots this year, as the CDC does not recommend the nasal spray, which is being retooled after showing little effectiveness in past seasons.
The experts also said seniors need a pneumococcal pneumonia vaccination, which protects against a common and deadly complication of the flu.