Sunday, May 24, 2020

In JAMA, So the Whole day was not wasted.

I did a bit of old style medical review.

May 24, 2020
But Is It Useful?

Gary Hurd, Ph.D. | Retired; UC Irvine, Medical College of Georgia (+ industrial, and private)
Both USC [1] and Stanford [2] have recently released studies of a commercially promoted method to test for the presence of SARS-CoV-2 IgM and IgG antibodies in blood. They applied their results to estimates of the larger population covid-19 prevalence.

These studies must address three questions; it is accurate, is it representative, and is it useful?

Is It Accurate?

The same rapid antibody test is used in both studies. It is a variant distributed by Premier Biotech, but made by Hangzhou Biotest Biotech of China. It was imported and widely distributed under multiple marketing names, and companies. The US FDA has not approved this method, and the manufacturer has withdrawn it. [3]

Premier Biotech primarily markets drug testing kits used in sports, and some industrial/commercial drug testing situations. USC group received funding from The Foundation for Clean Competition, The Partnership for Clean Competition [4]. Both are closely associated with Premier Biotech [5].

A preprint provides an additional unrefereed critical review entitled “Test performance evaluation of SARS-CoV-2 serological assays [6]"

Is it Representative?

A major objection to the Stanford version of this study was that they had drawn a sample not representative of the population they claimed to model. The USC version tried to repair this by using a commercial marketing firm to generate their sample. However well intended, the sample design was not followed. The samples in both studies were grossly biased toward upper-middle class middle-aged white women. These studies failed to be representative and cannot be generalized.

It is Useful?

A biologically accurate immunological test for our body’s reaction to SARS-CoV-2 is needed. But reported data from the USC study questions if the tested method is any better than self reported symptoms. Specifically two reported facts by USC call this into question.

First, 28.6% of the total sample report prior symptoms. This returns to the “representative” question.
Second, of the volunteers 72% of total positives had also reported prior symptoms.

Urging people who experience symptoms to get a direct swab test will be far cheaper and more effective than the serological test procedures used here.


[1] Sood N, Simon P, Ebner P, et al. Seroprevalence of SARS-CoV-2–Specific Antibodies Among Adults in Los Angeles County, California, on April 10-11, 2020. JAMA. Published online May 18, 2020. doi:10.1001/jama.2020.8279

[2] “COVID-19 Antibody Seroprevalence in Santa Clara County, California”
Eran Bendavid, Bianca Mulaney, Neeraj Sood, Soleil Shah, Emilia Ling, Rebecca Bromley-Dulfano, Cara Lai, Zoe Weissberg, Rodrigo Saavedra-Walker, James Tedrow, Dona Tversky, Andrew Bogan, Thomas Kupiec, Daniel Eichner, Ribhav Gupta, John Ioannidis, Jay Bhattacharya
medRxiv 2020.04.14.20062463; doi:


[4] The Partnership for Clean Competition, “… funds 80% of the worlds anti-doping research and development. Apply for a grant today!”

[5] "With Sports On Hold, A U.S. Anti-Doping Organization Switches Gears To COVID-19 Research" Karen Price | April 09, 2020 | Team USA. org

[6] Jeffrey D. Whitman, et al, “Test performance evaluation of SARS-CoV-2 serological assays” May 17, 2020. medRxiv