Right here’s image illustrating the distinction between the PCR and Fast Check. A PCR amplifies DNA and so if taken on the proper time it would detect the virus earlier than a fast check will. However this occurs when there isn’t a lot viral load and too little of the virus to be transmissible. Furthermore, at these occasions, the virus is growing quickly so the fast check will discover the virus tomorrow. The PCR check may even choose up fragments after transmissiblity has handed which additionally isn’t very helpful. A fast check could be very delicate for doing what it’s speculated to do, figuring out durations of infectiousness.
Michael Mina has achieved an ideal job selling fast exams and I do suppose we’re starting to see some recognition of the distinction between contaminated versus infectious and the significance of testing for the latter. What’s irritating is how lengthy it has taken to get this level throughout. Paul Romer made all the important thing factors in March! (Tyler and myself have additionally been pushing this view for a very long time).
Specifically, again in March, Paul confirmed that frequent was way more vital than delicate and he was calling for tens of millions of exams a day. On the time, he was discounted for supposedly not focusing sufficient on false negatives, regardless that he confirmed that false negatives don’t matter very a lot for an infection management. Individuals additionally claimed that tens of millions of exams a day was unattainable (Reagents!, Swabs!, Bottlenecks!) they usually weren’t impressed when Paul responded ‘throw some delicate drink cash on the downside and the market will remedy it!’. Paul, nevertheless, has turned out be appropriate. We don’t have these exams but however it’s now clear that there isn’t any technological or financial barrier to tens of millions of exams a day.
Go yell at your member of Congress.