Officials at the Centers for Disease Control and Prevention say 1 in 13 doctor visits last week were for symptoms of the flu. It reported the highest rate of flu-like illnesses since the flu pandemic of 2009.
Hospitalizations are "significantly higher" than the devastating 2014/15 season and with several more weeks of flu season she said "more deaths are likely to happen".
Meanwhile, health officials on Saturday confirmed the third pediatric death of the 2017-2018 flu season in New York City.
'The hospitalization rate is approaching the final rate that we observed at the end of the active 2014 flu season, ' Dr Schuchat said.
During an intense season like this one, it is possible to get an infection with both A-strain viruses and B-strain viruses at the same time, and people definitely get sick twice from the flu, with first one strain and then another, she said.
Even though the flu vaccine has low effectiveness against H3N2 viruses, it is more effective against other flu viruses, Schuchat said. The vaccine may also reduce the severity of symptoms if you catch the flu despite getting vaccinated.
The virus is still widespread in 48 states, bar Hawaii and OR, which dropped down to regional level last week.
In previous severe flu seasons - not counting pandemics caused by newly mutated viruses - up to 56,000 people have died in a single year. the CDC estimated.
The CDC does not count the number of adult deaths, however Dr Jernigan previously said that he expects the number of pediatric deaths to be similar as the 2014 season that killed 148 children.
In the most recent week data were available, 10% of deaths in the nation were from influenza and pneumonia.
While most flu-seasons last about 16 weeks, some have gone as long as 20 weeks.
The virus causing the most illness has been around for decades.
The supply of the antiviral drugs used to treat patients with the flu exceeds the demand, although prescriptions are higher than in previous years, Schuchat said.
There are early indications, including data from Australia and Canada, that vaccination against H3N2 was less effective than usual this year, in the range of 10% to 17%, instead of the usual 30% or so. "Flu is incredibly hard to predict, and we don't know if we've hit a peak".
"This season is a wake-up call about how severe influenza can be and how we can never let our guard down", she said.
"We recognize that this issue is personal to so many families and that there is a lot of fear and alarm", she said.