The nation is seeing its worst flu outbreak in more than a decade, with the CDC estimating there have already been 78,000 hospitalizations since the start of the season in October.
For weeks, flu hospitalizations have remained at a decade high. Nearly 20,000 lab-confirmed flu patients were hospitalized Thanksgiving week, marking a nearly 74 percent increase from the 11,269 flu patients admitted the previous week. The overall cumulative flu hospitalization rate is 16.6 per 100,000.
Seven more notes on this year's flu season:
1. So far this season, the CDC estimates there have been at least 8.9 million flu illnesses, 78,000 hospitalizations and 4,500 deaths.
2, Adults 65 and older have the highest rate of hospitalization (39.9 per 100,000), followed by children younger than 4 (28.4) and adults ages 50 to 64 (16.6).
3. Some of the groups most at risk of hospitalization — such as young children and adults 65 and older — have lower vaccination rates compared to this time last year, CDC Director Rochelle Walensky, MD, said during a Dec. 5 call with reporters. Among pregnant women, flu vaccination coverage is 36.5 percent, about 12 percentage points lower than last year.
4. Early data indicates this year's flu shots are a good match to the circulating strains, Dr. Walensky said during the CDC's latest update on the flu.
"We look in real time as to how well we think the influenza match is to what's circulating. And right now, the good news is that it looks like it is a very good match," Dr. Walensky said.
Firm estimates, however, will not be available until the spring, when the agency begins releasing results from its ongoing vaccine effectiveness studies, CBS News reported.
5. The majority of influenza cases detected this season have been H3N2, an influenza A variant associated with more severe illness. Read more about H3N2 here.
6. All viruses collected and evaluated this season have been susceptible to the four antiviral treatments recommended for flu patients, according to the CDC.
7. Health experts say the flu's early arrival this year is in part to blame for the high rates of activity and hospitalizations, because many people were infected before they were able to get vaccinated. Flu season typically peaks in January or February.