An estimated 80,000 people died of the flu and complications arising from the virus last winter, making it the deadliest flu season in at least 40 years.

Dr. Robert Redfield, director of the Centers for Disease Control and Prevention announced the number in an interview with the Associated Press. In recent flu seasons, deaths from the virus have ranged from about 12,000 to 56,000. Complications that can arise from the flu and result in death include stroke, heart attack and pneumonia.

The height of the flu season came in early February and had mostly subsided by the end of March.

The United States experienced an especially bad season last winter, driven by a particularly severe strain of the virus that led to more hospitalizations and deaths, especially among children and older people. In addition to a nasty strain, the flu vaccines weren't very effective, according to the AP.

Despite that, it is still important to get vaccinated, as it makes the flu less severe, and Redfield told the AP that he would "like to see more people get vaccinated."

The CDC cannot give an exact number of deaths that resulted from the flu because not all cases are reported and the flu is not always listed as cause of death on death certificates. In order to determine an estimated number, the agency uses statistical model, which are periodically revised, AP reported.

Although the estimate of 80,000 deaths may slightly change based on the model, officials say the death toll is not expected to go down.

According to available records, 2017-2018's flu season was the worst since the 1976-1977 season. However, it was not as bad as the 1918 flu pandemic, which lasted two years and historians estimated killed 500,000 Americans.