Antibody tests may be available within 2 months. These would show if someone has already been exposed to coronavirus without a positive test or even having suffered from obvious symptoms.
From The Mercury News on 2020 04 13
Stanford is now able to test 500 samples per day. Its experts are identifying who will receive the test first, with health care workers and other hospital staffers getting priority. What’s limiting more widespread use, said Montine, is the availability of the special robots used to run the test. There aren’t enough.