In total, 965 cases of the flu have been confirmed by health authorities in the province, with just more than 250 requiring hospitalization, he explained.
"Sadly, five Albertans admitted to the ICU have died," Horne said, emphasizing that the age and health of the patients was unusual.
"It is concerning that we are seeing younger, working-age adults being hospitalized," he said.
So far, only around one in five residents have gotten flu shots, which, Horne emphasized, are needed to protect "you, your friends, family, co-workers and everyone you come into contact with.
"That includes vulnerable Albertans for whom the flu can mean serious illness or even death," he stressed.
To encourage vaccination efforts, the province has increased the number of centers offering the shot and extended the hours. Local television showed long lines in the cities of Edmonton and Calgary.
The peak of the flu season typically comes in February, according to health authorities who fear a surge in cases that could overwhelm health centers.
In some parts of Alberta, "influenza is starting to clog emergency rooms, limit access to hospital beds and put strain on other health care resources," Horne said.
The outbreak is also starting to spread to other provinces, and one person reportedly died from the flu in Ontario.