The flu has been particularly bad this year among young and middle-age adults, according to a new report from the Centers for Disease Control and Prevention.
So far this flu season, 61 percent of all flu hospitalizations have been among adults ages 18 to 64 — an usually high percentage for this age group compared with previous seasons. During the last three flu seasons, adults in this age group have accounted for about 35 to 40 percent of flu hospitalizations, according to the CDC.
Deaths in this age group are also up: This flu season, about 60 percent of flu deaths have been among those ages 25 to 64. Last season, this age group accounted for just 18 percent of flu deaths, according to the report. [6 Flu Vaccine Myths]
"Younger people may feel that influenza is not a threat to them, but this season underscores that flu can be a serious disease for anyone," Dr. Tom Frieden, director of the CDC, said. "It's important that everyone get vaccinated."
Because flu season is still going on, it's not too late to get vaccinated, Frieden said. The CDC recommends yearly flu vaccines for everyone ages 6 months and older.
The type of flu viruses in circulation this year could be one reason that flu is affecting more young people. The predominant flu strain in circulation this season is H1N1, the same flu strain responsible for the 2009 "swine flu" pandemic, which caused high rates of hospitalizations and deaths among young people at that time as well. The current flu season is the first since 2009 to have H1N1 as the predominant flu strain, according to the CDC.
"It's back this year, and it's hitting younger people hard," Frieden told reporeters today (Feb. 20).
Some reassuring news is that this year's flu vaccine is doing at good job at protecting against flu, said Anne Schuchat, director of the CDC's National Center for Immunization and Respiratory Diseases.
"This season's vaccines are proving solid protection for people of all ages," Schuchat said.
Getting vaccinated reduces people's risk of having to visit the doctor for flu by 61 percent, the CDC said. The H1N1 viruses in circulation are similar to those included in this year's vaccine, the CDC said.
However, people ages 18 to 64 were less likely to be vaccinated this year, compared with other age groups. About 34 percent of 18- to 64-year-olds were vaccinated by November 2013, compared with 61 percent of those ages 65 and older, and 41 percent of children.
This lower vaccination rate may be one reason for the higher-than-usual hospitalizations and deaths in this age group, Frieden said.
Although last year's flu vaccine did not offer significant protection for older adults in terms of preventing doctors' visits for flu, this year's vaccine appears to be more protective for this age group, reducing the risk of visiting the doctor for flu by 52 percent.
People who get the vaccine may also be less likely to experience severe symptoms if they do catch the flu, according to previous research.
Schuchat noted that this season is not over yet, and estimates of the vaccine effectives could change.
For people who do become sick with flu, antiviral treatments are available, but it is important to start treatment as soon as possible, ideally within 48 hours of onset of symptoms, according to the CDC. Antiviral treatment is recommended for people with severe illness, and for those who are at high risk of serious complications from flu, such as older adults and people with chronic medical conditions.