By: Ted Dabrowski and John Klingner
One of the keys to fully reopening Illinois’ economy is knowing just how lethal COVID-19 truly is and yet, more than three months into the crisis, Illinois health officials have yet to provide any real guidance on what Illinois’ actual fatality rate might be.
More precise fatality numbers in Illinois would inform all kinds of decisions from what parts of the population need the most medical attention to how quickly the state can open up its economy. Instead, Illinoisans and its policy makers are left only with official COVID-19 numbers that grossly overstate the state’s actual death rate. That’s largely because Gov. J.B. Pritzker has stonewalled antibody testing in Illinois since late April.
Silence from the governor was understandable earlier on since preliminary predictions nationally put the COVID-19 death rate as high as 3.4 percent and it was impossible to reasonably estimate how far the infection had spread. But now antibody testing results from around the country, including from the CDC, are showing the actual lethality of the virus is far lower than originally feared.
Antibody test results are supplementing other tests and showing the true number of positive COVID-19 cases – current and recovered – may be anywhere from 10 to 50 times higher than the number of officially reported cases, dramatically reducing the virus’ actual fatality rate to a range of 0.1 to 0.5 percent.
That’s far lower than Illinois’ officially reported known-case fatality rate of 4.89 percent, which captures, by definition, only those who were sick with COVID at the time they were tested. Illinois’ known-case fatality varies massively by age range, from just 0.1 percent for 20-29 year olds to nearly 32 percent for those 80 years or older.
The exaggeration of Illinois’ death rate – on average about 20 times higher than what antibody testing demonstrates – is what makes that testing all the more urgent in Illinois.
Antibody tests show COVID’s real lethality
Antibody tests are being used in many parts of the country to determine what the true infection rate for COVID-19 is. Those tests identify people who’ve already been infected by the virus, in particular those who were asymptomatic or who only had mild symptoms and were never originally tested.
The CDC’s most recent results provide a better guidance on what the true death rate may be. Based on blood samples taken around the country, Robert Redfield, the CDC Director, said this last week: “CDC has completed a series and will continue to do fairly extensive surveillance throughout the nation using antibody testing. And our best estimate right now is that for every case that was recorded, there actually are ten other infections.”
The CDC findings suggest, then, that the true number of U.S. cases total 24 million, not the 2.4 million reported officially. That would drop the virus fatality rate to 0.5 percent from the known-case death rate of 4.9 percent.
Other city and state specific serological studies predict the number of actual positive cases to be even higher. A study in Miami-Dade County estimates actual COVID-19 cases to be 16 times higher than the county’s officially reported case number. Researchers from Stanford in Santa Clara, California found results that estimate 50 times as many cases than Santa Clara officially had. Other studies from Sweden put the estimates at even higher multiples.
The CDC said in a May report that its best estimate of what it calls the symptomatic case fatality ratio was 0.4 percent for the overall population. Adjusting for the asymptomatic cases not captured in that statistic, the overall infection rate fatality ratio drops to 0.26 percent.
Gov. Pritzker has refused to pursue antibody testing, so there are no good infection fatality rate estimates for Illinois. However, using Illinois’ data and antibody testing results from other parts of the county, the state’s infection fatality rate could range from 0.1 percent to 0.5 percent.
Antibody testing data is particularly important to the elderly population, who have suffered the most from the virus, by far. The official death rate is frightening, since it shows nearly one in six known victims aged 60 and older have died. The true numbers for Illinois won’t be known until significant antibody studies are done here.
Antibody testing is controversial when it comes to reliance by individuals. That’s because some tests on the market are error-prone, and it is not clear how much immunity one has if antibodies are present. But the FDA has confirmed that at least two tests on the market are 99% accurate, and researchers can adjust for error rates. Testing in Illinois, therefore, should be ongoing, just as it is in other parts of the country.
While the lower fatality rate from antibody testing is good news, it also means the disease has spread further than anticipated. In the long-term, that may increase the potential for herd immunity to reduce the spread of COVID-19. But in the near term, the fact that so many people are asymptomatic means it will remain harder to protect vulnerable populations.
The bottom line is, while COVID-19 is still more dangerous than the flu, it’s far less dangerous on average than initially believed. But averages can be deceiving, leaving certain groups in great danger. That’s why we need antibody tests. COVID-19 remains an extremely serious disease and its course continues to confound experts.
Illinois should be a leader in antibody testing nationwide, especially since the state has had the fifth-most cases in the country and the fourth-most deaths Unfortunately, Gov. Pritzker has said nothing recently about reinstating testing. In the name of science and data, that’s something on which he should immediately reverse his stance.
Read more about COVID-19 and Illinois property taxes:
- Illinois homeowners beware, COVID-19 means even higher property taxes
- Pritzker Says Masks ‘Turned the Corner’ on COVID-19; Data Say Otherwise
- New North Carolina antibody study shows far more people infected with COVID-19 than official numbers show
- Illinois downstaters had it right all along. COVID-19 data shows Pritzker should have reopened downstate weeks ago.
- New study finds ‘no evidence’ of COVID outbreak in Wisconsin after lockdown order voided; other metrics continue to improve