Influenza immunization rates in children are up this year compared with last but are unchanged in adults, with 36 percent of each group getting the vaccine by the middle of November, government officials reported.
Once offered only to the elderly and chronically ill, the flu vaccine is now recommended for everyone older than 6 months.
Although the target population is 305 million people, vaccine manufacturers expect to make no more than 173 million doses this season because many people forgo the shot.
So far this season, about 129 million doses of vaccine had been delivered to clinics, doctor’s offices, pharmacies, hospitals and workplaces, and 111 million people had received it, officials at the Centers for Disease Control and Prevention said.
Since 2008, the CDC has urged parents to immunize all of their children, in part because flu mortality among the young was higher than previously realized. Last winter, 120 children died. Two years ago, when the novel strain of H1N1 “swine flu” virus appeared, 282 children died.
This year, Hispanic children have been vaccinated at a higher rate (43 percent) than black children (36 percent) or white children (34 percent).
Among adults, vaccination use through mid-November was higher in whites (40 percent) than blacks (28 percent) or Hispanics (26 percent.) That is largely unchanged from last year.
CDC officials think it is especially important for health-care workers to get vaccinated against influenza because of their contact with elderly people and patients with chronic illnesses, both of whom are at higher risk for complications from the infection.
As of mid-November, 63 percent of health-care workers (which include people working in nursing homes) had been immunized, compared with 56 percent this time a year ago.
Among those not vaccinated, 32 percent said they didn’t think vaccines worked and 18 percent said they thought the vaccine might make them ill.
Flu vaccine is 50 to 80 percent effective in preventing illness. The flu shot cannot cause influenza, because the virus it contains is inactive.
Influenza has not begun to circulate widely in the United States, although sporadic cases have been reported in 29 states and the District of Columbia.
“We’re seeing very little, but that doesn’t mean that it isn’t just around the corner,” Anne Schuchat, director of the CDC’s National Center for Immunization and Respiratory Diseases, told reporters by telephone Monday.
This season’s vaccine is the same as last year’s. It contains inactive versions of three different strains of flu virus that have been circulating for at least two years. The CDC recommends that people get vaccinated even if they were last year, as the duration of immunity varies considerably.