I had a physical checkup scheduled for March (the U.S. health care system had so much spare capacity prior to coronaplague that it took only 3 months to get on the schedule). As part of this, the doc ordered some bloodwork. Of course, everything has been pushed back until at least June. But I thought I would call the doc to see if he would add a coronaplague antibody test.
“Don’t do it yet,” he told me over the phone. “Everyone is waiting for the Mount Sinai test, which should be available in a couple of weeks.”
He said that even the best of the existing tests, such as the one from Roche, suffer from being triggered by previous infection to unrelated coronaviruses, e.g., due to a common cold a year previously. This is at variance with the Roche press release, so I am not 100 percent sure that he is correct, but since there is nowhere to go right now maybe waiting a couple of extra weeks doesn’t matter.
The antibody tests have been systematically downplayed in recent days in favor of armies of contact tracers. Until as recently as last week, Andrew Cuomo was touting NYS’s home-grown antibody test but the backlash was already brewing. I listened to NYS Department of Health Commissioner Howard Zucker describe their tests as being “six standard deviations out” – whatever that means – while championing its accuracy on NPR about a week ago. These were supposed to be the creme-de-la-creme, the gold standard, the ne plus ultra of antibody tests in the USA.
Quashing the antibody test results is crucial because they don’t want anyone using them as arguments to reopen the economy. You can read about the evolution in the messaging here:
https://www.nydailynews.com/coronavirus/ny-coronavirus-new-york-antibody-test-concerns-medical-community-20200511-kiv7bfpk3bepnbol3fcbemynju-story.html
“A month ago, the governor was among those touting the benefits of the testing, offering a glimmer of hope as the state mulled the gargantuan task of reopening the economy and controlling the virus going forward.”
…
“We use the antibody test more for an indicator for infection rate,” he said during a briefing Friday in Poughkeepsie. “We’re not taking action off that antibody test. It’s not like we tell you, ‘OK, you can go back to work now because you’re safe.’ We use it more for statistical purposes.”
…
““We shouldn’t be selling it as this back-to-work piece because we don’t want people changing practices — social distancing and hand washing,” she said.”
You can witness how the Commandment came down from figurative Mount Sinai over the past few weeks:
“Thou Shalt Not Use Positive Antibody Tests To Suggest Immunity”
If you Google: “Howard Zucker Antibody Tests”
https://www.google.com/search?q=Howard+Zucker+Antibody+Test&oq=Howard+Zucker+Antibody+Test
The change from early April to today is very close to a 180. The New York Times ran a story yesterday to reinforce the new Commandment.
https://www.nytimes.com/2020/05/13/opinion/antibody-test-accuracy.html
They don’t want anyone with a positive antibody test thinking they can leave the Church.
It’s a little like the biker scene from “A Bronx Tale”:
“Now Youse Can’t Leave”
I had heard the Abbott one was pretty good:
https://news.ycombinator.com/item?id=23143224
Reports from the UK indicate that the Roche antibody test was reliable (so far), and say nothing about being triggered by unrelated coronaviruses: https://www.bbc.com/news/health-52656808
A friend of mine works in a health system that uses Beckman Coulter stuff (a large provider of diagnostic tests and lab equipment.) They recently released their covid antibody test. The specificity/sensitivity numbers look good. They are specific about which antibodies they are detecting. Their assay detects antibodies to the RBD (Receptor Binding Domain) of the spike protein.
http://www.beckmancoulter.com/en/products/immunoassay/access-sars-cov-2-igg-antibody-test