The FDA has approved the first at-home, over-the-counter HIV test, which could potentially inform thousands of Americans about their HIV status.

The OraQuick In-Home HIV Test can detect antibodies of the virus from a saliva sample. It can provide results without a laboratory in 20 to 40 minutes.

About 1.2 million people in the U.S. are infected with HIV, and an estimated 20% of those infected are unaware that they are HIV-positive, according to the CDC.

The outcome of the test isn't definite or absolute, especially when exposure may have been within the past three months. Clinical studies expect one in 12 tests to read a false negative and one in 5,000 tests to read a false positive. At an FDA Advisory Committee meeting in May, officials said they thought an additional 45,000 people would learn they have HIV through the test.

FDA officials said the test will offer a different testing method for many unknowingly HIV-positive Americans that are unlikely to get tested at clinics and other screening centers.

"The availability of a home-use HIV test kit provides another option for individuals to get tested so that they can seek medical care, if appropriate," Karen Midthun, MD, director of the FDA's Center for Biologics Evaluation and Research, says in a news release.

An estimated 50,000 Americans are infected with HIV each year, and the resulting AIDS condition claims 14,000 lives annually, according to the CDC.

The test is made by OraSure Technologies and will be available in October. The company will have a consumer support center available to help users with using the kit and understanding the results. Although no price has been set, a company official said in May that he expected the price to be lower than $60.