By: Mark Glennon*
Aside from routine testing for current COVID-19 infections, other tests look for antibodies that indicate previous infection, perhaps without the victim even knowing it. They’re called “serology tests” and they are important because those who were previously infected are widely thought to be immune, at least to some significant degree, from further coronavirus infection.
An excellent article in the Chicago Tribune Friday covers the results of antibody testing on Chicagoans. Nearly 1 in 5 Chicago residents tested positive for antibodies to the coronavirus that causes COVID-19, according to preliminary results of an ongoing study by Northwestern University researchers, reports the Tribune. That 20% rate is far higher than thought to be common. The Center for Disease Control, for example, currently estimates that only about 10% of the nation has antibodies.
Think about what that means. It means about 540,000 Chicagoans have been infected, which is over six times more than the 83,500 officially reported number of cases. The number of “cases,” which you always see reported, is just the number of those who have tested positive for a current infection. Obviously, actual number of infections in people who never got tested because they never got sick is vastly higher.
And the chances of getting infected are therefore also far lower than commonly thought, at least in Chicago, if the study’s initial results are accurate. That’s because those who were already infected have the antibodies that provide a level of immunity.
Since April Wirepoints has criticized the State of Illinois’ refusal to collect and publish antibody test results. If Illinoisans are to have an accurate understanding of the true risks they face from coronavirus, serology test results are essential.
But those test results can only point in one direction – toward less risk. It’s only a matter of how much less risk. That’s why we were not surprised by the results published by the Tribune. We suspect the state has no interest in collecting or publishing information that would indicate less risk. The state left it to the hit and miss of whether other groups would do any testing, and we are fortunate that the Northwestern researchers have taken up the task, at least for Chicago.
The state’s initial excuse for stonewalling antibody testing was the inaccuracy of many antibody tests, and earlier there was legitimate concern that individuals would foolishly rely on faulty tests to think they were immune.
But that never was an excuse for failing to collect the test results for research purposes and a broader understanding of the risks presented by COVID. For those purposes, researchers corrected for error levels. More importantly, better tests were on the market by May, with very high accuracy levels confirmed by the Food and Drug Administration, eliminating that excuse.
We still need better information on antibody testing and it should be statewide. Chicago’s high positive rate may not be typical, since the outbreak was initially concentrated there, but we should know. If containment efforts are to be directed smartly they should be informed by antibody tests that show where immunity levels are high or low.
More comprehensive antibody information would also be important to considering to the new line of thinking being embraced by thousands of scientists about how to deal with coronavirus. That’s what’s called the Great Barrington Declaration, described here, which has been signed by many of the world’s top epidemiologists.
Their view is that containment and distancing efforts should be narrowly targeted on high risk groups, and others should be encouraged to resume a normal life. They oppose mass restrictions and shutdowns. To properly implement that new approach it obviously would be useful to define high risk groups as precisely as possible, and antibody tests would be extremely useful for that.
Just don’t expect to hear any of that from the State of Illinois.
*Mark Glennon is founder of Wirepoints.
More of our original stories on COVID-19 are collected here.