RE:ABSOLUTE GAME CHANGERI agree Starsearcher80. This is a game changer, especially for airlines. Sure hope the saliva-based home tests are approved soon. Here are some excerpts from today's WSJ article on the subject and from an article last week in the Financial Times.
Public Health Officials Pursue Covid-19 Tests That Trade Precision for Speed (WSJ) Public health experts are increasingly calling for a shift in thinking about Covid-19 testing: It is better to get fast, frequent results that are reasonably accurate than more precise results after dayslong delays.
Diagnostic companies are racing to develop
quicker, cheaper Covid-19 diagnostic tests, and tests that can be done at doctors’ offices, nursing homes and other places with the assistance of a medical provider are gradually becoming more widespread.
The U.S. Food and Drug Administration has authorized four such tests that are antigen-based, meaning they search for viral proteins. Test makers have vowed to produce tens of millions of these quick-turnaround tests in coming months, including
Abbott Laboratories which recently unveiled
a test that costs $5 and is the size of a credit card.
Several companies also are working on at-home rapid tests that people can perform themselves. No test is currently authorized for complete at-home use, in part due to regulatory requirements for ease-of-use and accuracy.
Covid-19 tests that don’t require a lab tend to be less sensitive than “gold standard” laboratory-based tests, meaning they are likely to miss more cases. But many public health experts now say that repeat testing can make up for the loss of sensitivity, and such testing could quickly identify the most infectious people and help bring transmission to heel as workplaces and
schools resume in-person operations and as
influenza season looms.
“When we looked ahead, we realized we needed a paradigm shift from the still-needed diagnostic tests to the screening tests,” said Jonathan Quick, managing director for pandemic response, preparedness and prevention at the Rockefeller Foundation, which
released a report in July calling for a massive scale-up in quick, cheap tests for Covid-19 screening. “As a practical matter, that meant making much more of a new kind of test,” Dr. Quick said.
What is needed, some public-health specialists say, is a shift to cheaper, more routine testing among people who don’t show any symptoms to identify those who can potentially spread the virus. That would involve making a distinction between Covid-19 testing for patient diagnosis and testing for public-health screening.
For one-shot diagnostic testing, doctors need tests that are relatively quick but as accurate as possible. But for screening purposes in settings such as workplaces or prisons, a less-sensitive test, such as an antigen test, would be good enough to catch most cases and isolate those with an infection while relieving pressure on labs.
With frequent testing, cases missed the first time around might be caught a few days later. That is more effective for screening than a highly-accurate test done once a month or once a week, which would give the virus more time to spread, public health authorities say.
“If you wait a week, it’s too late,” said David Walt, co-leader of the Mass General Brigham Center for Covid Innovation in Boston and co-founder of Sherlock Biosciences, a diagnostics company that is working on point-of-care and at-home Covid-19 testing based on
Crispr gene-editing and synthetic biology technologies.
Antigen tests are better at identifying cases when people have more virus in their system—meaning they will likely find people when they are most infectious, said Michael Mina, an epidemiologist at the Harvard T.H. Chan School of Public Health and an advocate of low-cost, widely available at-home testing that can be done on a paper strip.
A high regulatory bar for authorization is one reason quick, at-home testing for consumers has yet to hit the market, said David McManus, co-director of the Center for Advancing Point of Care Technologies at UMass Medical School, who is involved with the RADx program.
There is a similar recent article in the London Financial Times. That article provides a link to the following research paper. https://www.medrxiv.org/content/10.1101/2020.06.22.20136309v2.full.pdf Mass testing offers hope of taming the pandemic
Governments should vigorously pursue new screening technologies Since the virus can be spread by infected people before they feel ill or who never show symptoms, only frequent, mass screening is properly effective. But existing so-called PCR testing requires chemical reagents and specialist machines, limiting capacity and pushing up costs. There are ways of squeezing more tests out of PCR capacity, including “pooling” multiple samples to be tested together then, if any positives are detected, identifying them through a process of elimination. Such efforts should be stepped up.
At least half a dozen companies, however, are working on cheap, self-administered saliva tests using paper strips that show a marker if the virus is found, similar to a pregnancy test. The drawback is they are less sensitive than gold-standard PCR tests, only returning a positive result for perhaps 85 per cent of infected people.
Regulators often approve only the most sensitive tests for a disease.
Yet a growing body of medical opinion suggests that the volume and frequency that cheap self-testing would permit more than compensates, overall, for higher false positives or negatives. A positive saliva test indicator could be followed by a PCR test, with people going into isolation if that confirms the result.
Scaling up such testing to allow entire populations to screen themselves, say, once a week would still cost billions of dollars — but would be cheaper than the cost of large-scale lockdowns. Employers might be ready to fund or part-fund testing of employees or, where appropriate, their customers. In coronavirus testing, the best should not be the enemy of the good, if “good” tests can be cheaply mass-produced and administered. Going down this route offers the best hope — without a vaccine — of returning to something closer to normal life.