Wall Street Journal: Testing for Coronavirus: What We Know About Covid-19 Tests and Treatment

As the U.S. quickly builds its capacity to test people for the new coronavirus, some researchers believe that as many as one in three infected people get inaccurate results, raising the chance they may infect others.

Still, completed tetts now number in the millions, a dramatic shift from just weeks ago, and experts are racing to develop treatments and vaccines.

We are updating this guide regularly with what we learn about testing and treatments across the U.S.

Can anyone who wants a test get one?

• As more tests are being distributed, the Centers for Disease Control and Prevention says doctors and health departments may decide whether a patient should be tested.

• Whether diagnostic tests are available depends on factors including where you live and the policies of local governments and your health-care provider. There still appears to be a mismatch between the number of people who need tests based on symptoms and those who actually get them.

• The CDC recommends calling your state or local health department or a medical provider.

Where in the country are tests being done?

• Ninety-five public health labs around the U.S. are using Covid-19 diagnostic tests, according to the CDC. The labs are in all 50 states, plus Washington, D.C., Puerto Rico, Guam and the U.S. Virgin Islands.

• Academic hospitals across the country have developed their own distinct methods, through methodology that they have developed and that the Food and Drug Administration has generally accepted. The result is a small number of communities where testing is often widely available, such as Roseville, Calif., near the University of California, Davis.

• CVS Health Corp. and other big drugstore chains have begun setting up drive-through sites outside stores. Walgreens offers tests to health-care workers and first responders at a Chicago-area site. Rite Aid plans testing at a Philadelphia site, and a CVS testing site in Shrewsbury, Mass., has opened. The locations are run by health officials and aren't open to the general public. People getting tested need to stay in their cars.

Do testing numbers match the number of actual infections in the U.S.?

• As of Friday morning there were 461,437 confirmed cases and 16,478 deaths in the U.S., according to data from Johns Hopkins University.

• The number of confirmed cases is substantially lower than the number of infections, public-health officials say. Along with a shortage of tests, many people who get infected might not be sick enough to realize it or can't get a test.

How do tests work?

• Current tests for live infections use nasal swabs to collect samples for testing. RNA is extracted, isolated and processed through a device called a thermocycler that amplifies the amount of genetic material to identify it.

• Blood tests are being developed and licensed to test people for antibodies that people develop over time to the virus to determine who may have been infected in the past. A major hope of this effort is that people proven to have been infected and recovered may go back to work, especially in health-care settings. But it is vital that such tests in particular be precise—and that people are developing antibodies against this current virus and not some earlier coronavirus, such as a cold.

How long does it take to get test results?

• As with many medical tests, there can be a wait of as much as two to three weeks to get results, depending on where testing is done. Some processing, however, is as short as several hours or even minutes.

• LabCorp said it now can run about 40,000 tests for Covid-19 daily and that based on current volume levels, it can provide results within two to four days to the health-care provider from the date of the specimen pickup. Abbott Laboratories has a test that can give results within minutes, but these generally are at hospitals that use Abbott analysis machines.

What snags has the U.S. hit in expanding testing?

• CDC officials botched an initial test kit developed in an agency lab, retracting many tests. They resisted calls from state officials and medical providers to broaden testing, and health officials failed to coordinate with outside companies to ensure needed test-kit supplies, such as nasal swabs and chemical reagents, would be available, according to suppliers and health officials.

• Early on, the CDC restricted testing to people with virus symptoms who had recently traveled to China, where the virus first emerged, or had been exposed to a known case. That narrow effort was "a failing," said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.

• The Food and Drug Administration relaxed testing regulations on Feb. 29. Under its policy now, testing companies and academic hospital labs with ability to perform complex tests can do so with only retroactive review by the FDA of data verifying accuracy.

• Medical professionals have limited supplies of the swabs and chemicals known as reagents needed to conduct the tests and personal protective equipment needed for those who treat patients. This still is a factor limiting numbers of tests.

Are tests accurate?

• Health experts say they now believe nearly one in three patients who are infected are nevertheless getting a negative test result. They caution that only limited data are available, and their estimates are based on their own experience in the absence of hard science.

• That picture is troubling, many doctors say, as it casts doubt on the reliability of a wave of new tests developed by manufacturers, lab companies and the CDC. Most of these are operating with minimal regulatory oversight and little time to do robust studies amid a desperate call for wider testing.

• The FDA said it has prioritized getting new tests out and that it is unable now to disclose the rate of test inaccuracies. Two members of Congress, Reps. Lloyd Doggett (D., Tex.) and Rosa DeLauro (D., Conn.) wrote to FDA Commissioner Stephen Hahn on April 9 asking for labs' data on the new tests' precision.

How many Americans have been tested?

• The CDC isn't reporting how many people have been tested. The Covid Tracking Project, a volunteer effort to collect data from public health authorities and other sources, reports nearly 2.4 million completed tests in the U.S. as of April 10.

What treatments are in the works?

• Possible treatments for Covid-19, the disease caused by the novel coronavirus, are all experimental or have only emergency-use approval, as opposed to full approval from the FDA.

• One is called remdesivir. It is a drug from Gilead Sciences that senior officials at the National Institutes of Health believe may have promise. It is in a clinical trial that could be as brief as two months, but there have been drugs before that had promise but failed in clinical studies. You can learn more about the Gilead-initiated clinical trials at the company's website.

• Another is known as "convalescent plasma," which uses the colorless fluid in blood that contains antibodies that are produced to fight infections. The plasma taken from recovered Covid-19 patients contains antibodies particular to the virus. This approach has worked in some respiratory viruses before, though the plasma from one patient can treat only one or two others. The approach was FDA-endorsed on an "emergency use" basis, meaning it can be used during the pandemic, but not necessarily beyond. You can learn more about how to seek treatment and to donate plasma from the National Covid-19 Convalescent Plasma Project, a collaboration of doctors and scientists in 17 states.

• On the horizon are possible novel treatments. Drugmakers including Vir Biotechnology Inc., AbCellera Biologics Inc. and Regeneron Pharmaceuticals Inc. are all pursuing therapies. Overall, more than 120 drug and vaccine research programs aimed at the coronavirus are under way. Ten agents are being studied in some 200 clinical trials, and hundreds more trials are planned, many spearheaded by universities and government research agencies.

What about hydroxychloroquine and chloroquine?

• These are years-old drugs approved for malaria, with limited evidence from small studies in France and China, so the FDA is overseeing a clinical trial. The agency also says the drugs are being distributed from the Strategic National Stockpile for doctors to prescribe "when appropriate" and a clinical trial isn't available.

• Various studies are taking place of these drugs, including an effort by Intermountain Healthcare and the University of Utah in Salt Lake City. They said it would be the largest trial to evaluate hydroxychloroquine and chloroquine, and are seeking to enroll 2,300 patients. Also, an NIH-backed study of hydroxychloroquine in 500 patients with coronavirus has begun at Vanderbilt University Medical Center and other hospitals.

• But because the drugs are also needed for other conditions, including lupus, some states are limiting prescriptions or demanding proof of a Covid-19 diagnosis.

How far away is a vaccine?

• There is considerable hope that a vaccine may arise out of the pandemic that could protect people, perhaps as soon as some time next year. One that arose out of work at Moderna Inc. and the National Institute of Allergy and Infectious Diseases has already entered human testing, among 45 adults in the Seattle area.

• Other companies, including drugmakers Johnson & Johnson, Sanofi SA and Inovio Pharmaceuticals Inc., are also seeking to develop Covid-19 vaccines, and J&J said recently that it could start human trials as soon as this fall.