unfortunately, that's become a near impossible cohort to select for accurately.
you cannot prove a negative like that.
"never diagnosed with covid" and "never had covid" look the same in the patient data, but are impossible to separate accurately without doing some kind of pathogen challenge test with blood. not even an antibody test would really manage it.
makes it really hard to get a cohort of any scale.
It's possible but expensive, and not profitable. The research labs can do flow cytometry on B-cells and then check induced antibody responses. It's as manual and tedious as it sounds.
unfortunately, that's become a near impossible cohort to select for accurately.
you cannot prove a negative like that.
"never diagnosed with covid" and "never had covid" look the same in the patient data, but are impossible to separate accurately without doing some kind of pathogen challenge test with blood. not even an antibody test would really manage it.
makes it really hard to get a cohort of any scale.
Could this be one of the reasons that the control group was done away with in the "trials"?
Why would you think that? A second lieutenant wouldn't even dare think that.
It's possible but expensive, and not profitable. The research labs can do flow cytometry on B-cells and then check induced antibody responses. It's as manual and tedious as it sounds.