A brief update on two new developments that have the potential for being game changers.
Quidel Corporation has announced that they have come up with the long-desired antigen test. Antigen tests look for pieces of viral or bacterial proteins. They do not have the capability to test for pieces of viral genetic material. They are less accurate than the RT-PCR tests that are the current gold standard for deciding whether a patient has an active infection.
Antigen tests have a huge upside. The machine that reads them is small (smaller than a toaster oven), and not prohibitively expensive. They can be deployed at sites far removed from large urban centers. The results take 15 minutes or less. The specimen sample can be obtained by a regular swab, from the nose or throat. Once a company like Quidel ramps up to make a million tests a week, the cost of testing is reasonable. It is likely that you or someone you know has had a rapid Strep or influenza test done. These are antigen tests.
There are downsides. The results are binary: either positive or negative. They cannot tell you how much viral material was found. They are set up to provide a minimum of false positive tests, which means that they come up with 10-15% of false negative tests.
With antigen testing, you cannot have it both ways, at least not with relatively inexpensive technology. You can set the needle to detect even the slightest inkling of viral presence to read positive, but that means that out of a thousand people who take the test, more than a hundred will be sent home to quarantine needlessly. Better to make sure that when you get a positive, it means positive. The adverse consequences of a false negative are mild. If you are gravely ill, the doctor will order a RT-PCR test anyway. If you have no symptoms, you may spread the virus to others, but in the presence of widespread affordable testing this is a chance we can take.
Two things make me optimistic about this development. Quidel has a long history with antigen testing: they are not newcomers. And there are at least six other companies on the same track to come up with their own tests, meaning that there should be plenty of testing capacity soon. Quidel has promised availability of a million tests a week by mid or late June. The FDA has approved the test.
The second bit of news is a paper from Hong Kong that examined the ability of three antivirals (all oral) plus one interferon injection to treat mild to moderate infections. Within one week there was a high rate of clearance of virus in these people. So, we know that at least the current version of the virus can be “killed.”
In my ideal world (my wife often reminds me that I’m not the king), schools, workplaces, and private citizens would have access to antigen tests. These are to be done at regular intervals, maybe once a week while the epidemic rages. People who test positive would have a confirmatory RT-PCR test if they so desire. Treatment with antivirals would be immediately available if doctors felt it necessary. There would be rechecks in two weeks. The greatest benefit of cheap tests and effective treatment will be psychological: people will no longer be afraid of going to restaurants. With time, we can have professional sports reopen.
In my ideal world, we would have a federal government that was already looking at how to build the policies and infrastructure that it will take to take advantage of this new knowledge. What do we do with the third grader who tests positive and feels great? Can we have special areas within or close to schools where these children can be taught and watched? Are we going to insist that one of these parents take the child home, at a time when everyone will need money?
How can we avoid the ostracizing of workers who test positive? How can we protect privacy while we reassure coworkers that their colleague is cured? Should we ask that every visitor to a nursing home be tested? Who will pay for this?
I think that we have the opportunity to begin a massive turnaround. Please, I do not want you to throw your masks away, or to take your weapons out of storage so that you can visit your legislator. These are preliminary advances. Although I feel that they will prove to be important, the virus could develop a lethal mutation, or one of many other complications can occur.
Stay the course, listen to people who know what they speak of, and remain hopeful.