The unidentified person was between the ages 50 and 64, the state Department of Public Health said. The patient's place of residence was not released.
The first death from the flu in Connecticut was reported a week ago.
That person was over the age of 65, the health department said.
Twenty-three people have been hospitalized in Connecticut as flu activity has been slowly increasing statewide since the end of August, which is typical for the flu season.
Nationally, flu activity has been minimal across the United States so far, according to the Centers for Disease Control and Prevention.
Last year, 154 in Connecticut and more than 80,000 nationwide died from the flu.
The flu season runs from October through May.
In September, Congress approved $140 million in new federal funding toward a universal flu vaccine. That is on top of a $40 million increase in federal funding for development of a universal flu vaccine secured earlier this year.
A flu vaccine is recommended for everyone 6 months of age and old annually, the Centers for Disease Control said.
People can continue to be vaccinated throughout the course of the flu season. Manufacturers expect to have about 163 million doses of the vaccine this season in the U.S.
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