A federal report released Wednesday estimated that 8 million American women ages 21 to 65 have not been screened for cervical cancer in the past five years. The report also noted that more than half of the cervical cancer cases occur in women who have previously never been or rarely been screened.

From 2007 to 2011, the cervical cancer rate nationwide fell by 1.9 percent a year and the death rate remained stable.

Still, the southern United States had the highest rate of cervical cancer (8.5 cases per 100,000 women), the highest cervical cancer death rate (2.7 deaths per 100,000 women), and the highest rate of non-screening in the past five years (12.3 percent).

“We must increase our efforts to make sure that all women understand the importance of getting screened for cervical cancer. No woman should die from cervical cancer,” CDC Principal Deputy Director Ileana Arias said.

Wider use of the human papilloma virus (HPV) vaccine could also help reduce cervical cancer cases and deaths from the disease, the CDC said. A recent study by the agency found that the vaccine is underused, with only 1 in 3 girls and 1 in 7 boys receiving the three-dose vaccination series in 2013.

The HPV vaccine is recommended for children ages 11 to 12. Studies show that HPV vaccination and cervical cancer screening combined could prevent as many as 93 percent of new cervical cancer cases, the CDC says.