Thread by @IBDMD

Improvements in testing for #SARSCoV2 and #COVID19 and how they will transform what we are doing (a Tweetorial):
1) FASTER VIRAL TESTS for SARSCoV2 (the virus). Several companies have adapted existing point-of-care tests that can provide results in MINUTES.
Read on ⬇️⬇️⬇️
1/

Faster tests for #SARSCoV2 may be less sensitive or specific for detecting the virus but we can figure this out.
Less sensitive means more false negative results (you actually have the virus, but the result says you don't).
Less specific means more false positive results.
2/

How do you enhance interpretation of a test with less sensitivity and specificity? You add other information, like the clinical scenario (fever, resp symptoms), known exposures (close contact with #COVID19, being a healthcare worker), and repeating the test after a bit.
3/

Think about this in terms of trade-offs. In general, the more sensitive a test, the less specific, and vice versa. You can read about Receiver Operating Characteristic curves in this helpful article by science writer Karen Steward: technologynetworks.com/analysis/artic…
But read on, please:
4/

2) SEROLOGIC ANTIBODY TESTING. What is that?
Blood tests for your body's antibodies against the virus (#SARSCoV2).
We know lots about the immunology of our antibody responses to infections, here is a slimmed down version.
5/

When your body is exposed to a foreign antigen, your immune system reacts to protect you. The immune system is complex and has both innate (built-in) and adaptive (acquired) defense mechanisms. The adaptive immune system has acute (immediate) and chronic (long-term) responses.
6/

The acute response of your immune system is the development of antibodies in a class called Immunoglobulin M antibodies. (there are others). The chronic response is most often characterized by Immunoglobulin G antibodies.
So IgM titers go up first, followed by IgG.
7/

So, want to know if you are already immune to something? Check the IgG titer. Example: many of us are required to have our Hepatitis B IgG titers checked periodically to make sure they remain protected against Hep B.
Back to #SARSCoV2
8/

We believe that people who are infected with #SARSCoV2 develop the traditional pattern of IgMs and IgGs.
How can we know that?
▶️Because there are studies looking at this very question from the 1st SARSCoV outbreak (2002), like this 2004 paper: ncbi.nlm.nih.gov/pmc/articles/P…
9/

What does this mean?
It means that if you have measurable IgG antibodies to #SARSCoV2, you are most likely PROTECTED against getting sick with #COVID19.
You've been IMMUNIZED against #SARSCoV2.
10/

Yes, IMMUNIZED against #SARSCoV2. In order to get this way, you needed to get exposed to the virus and for many people, that also means getting sick, so not the best way to do this but VERY IMPORTANT for those who get it.
▶️Can we do it better? Yes, but not yet.
Read on ⬇️
11/

Wouldn't it be great if we could get people IMMUNIZED against #SARSCoV2 without exposing them to the virus?▶️Yes, this is how VACCINES work- using parts of the virus that stimulate the right part of our immune system, we develop IgGs that protect us.
12/

We don't have a vaccine against #SARSCoV2, but we will get one.
In the meantime, knowing who has anti-SARSCoV2 antibodies can provide valuable information, but we need to make sure of a few more things.
❓Are these antibodies truly protective against infection?❓Do they last?
13/

But once we sort this out (quickly), we can do a lot:
▶️We can identify sick patients with #COVID19 from those who have other problems that can look like it.
▶️We can identify healthcare workers who are immune and hopefully are protected by their own body against #COVID19.
14/

AND... studies are underway now to use the serum of people who have the anti-SARSCoV2 antibodies (IgG) to TREAT those who are sick with #COVID19. (convalescent serum)
Here are the ones listed on clinicaltrials.gov

15/15 fin

@threader_app compile