Post-Covid Antibody Testing: Getting Back on Our Feet

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Here’s an interesting table of Covid-19 statistics (as of 9 am PDT March 17) to contemplate:

Country	Smoking Rate	Cases	Deaths	Death Rate
South Korea	23.3%	8,236	75	0.9%
United States	21.8%	1,714	41	2.4%

Which country is right about the death rate? Anthony Fauci is probably one of a half-dozen or so of the smartest people on this subject. He keeps saying that the death rate for Covid-19 is about ten time that for influenza, which is 0.1%. So he apparently thinks South Korea is right about the death rate.

What accounts for the difference? Testing. We all know South Korea has been doing a superb job of getting its people tested, with multiple drive-in testing centers around its big cities. We also know that we Americans have bungled the job.

So unless you think that South Koreans’ collective genetics makes them Covid-19 superheroes, there are approximately 1,714 x 2.4/0.9 - 1,714 = 2,857 people in the US who had or have unconfirmed cases of Covid-19.

Why is that important? If these statistics are right, at least 87.6% of them, or 2,502 people, either got or are getting well.

If we knew who they are—and once we were sure they are no longer infectious—they would be our first cohort of post-pandemic survivors. They could be the first ones to emerge blinking from the fallout shelter into the dawn of a new life.

Having natural immunity from having survived the disease, they could go anywhere and do anything without fear. In particular, they could volunteer (or be paid) to man testing sites, take care of the sick and buttress a health-care system under siege. They could go back to work or school. They could go back to restaurants, bars, shops, theaters, gyms, fly on planes, go on cruises, and begin jump-starting our wounded economy.

But how do we find these “survivors”? We need another test than the one that works for immediate infection, before the infected person has a chance to develop antibodies and therefore immunity. We need a test showing whoever’s been infected and is now immune, so that they can go back to normal life without fear, and without threatening anyone else.

There are some subtleties. The two tests—for infection and immunity—may overlap technically and practically; that’s a question for the microbiologists (I’m not one). One test may be more complex and/or expensive than the other. And there may some remanent period during which a recovering or recovered person can still spread the infection.

If the two tests are identical, the obvious priority is testing people getting sick, not those who got or are getting well. But even then, all people tested should remain identified, so that they can be “cleared” once well and deemed non-contagious. (We may have to modify our absurdly draconian medical-privacy laws here.)

Anyway, the longest remanence period for contagiousness of which I’ve ever read is 37 days. From now, that would end before the end of April. That’s many months before any expert estimate of the vaccine-development time.

Wouldn’t it be nice, as we contemplate a grisly conveyor belt moving sick people into hospitals and ICUs with ventilators, that there also be a conveyor belt moving people back to normal life? All that requires is an antibody test for those who’ve had the disease, have apparently recovered, and are now immune.

Producing and giving these tests would have to be a largely non-profit venture, probably government sponsored. The real push in microbiology is and must be to develop a vaccine. Once the vaccine arrived, it would render these antibody tests obsolete: get vaccinated, wait the requisite period (probably about two weeks), and you would have “presumed” immunity.

But an antibody test might still have some residual value: (1) in individual testing if the vaccine were not fully effective; (2) during the ramp-up to produce enough vaccine for everybody; and (3) if the antibody test cost less than the vaccine to produce.

The salient thing about this virus is that the overwhelming majority of people who get it are going to recover. So shouldn’t we start working on a good, cheap, simple antibody test to identify those who have recovered right now?

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