Antibody tests for #COVID19 will give us much needed info on a large scale population level.

We simply don’t know how many people have been exposed or *may* be immune at this time.

*If* these tests are reliable AND we can test millions of people we’ll be much more informed

Immunology 101: Antibodies are part of our humoral immune system.

We have initial responders (IgM) that are nonspecific and show up when something (virus/bacteria) doesn’t belong.

IgG is the 2nd wave AND has the ability to learn & remember specific info about the invader.

IgG antibodies *can* indicate immunity but are best suited to show past exposure. Levels will vary between people and over time in the same person.

Timing is everything - test too soon: Antibodies may not be found yet even if someone is actively infected.

Here’s the crux: If antibody tests are unreliable, we will see too many false positives and false negatives...and then make misinformed decisions.

This is inevitable with every test we use BUT need to control it as much as possible and know how often this occurs.

Unanswered questions:
1. What level of IgG indicates immunity?
2. How long does immunity last?
3. Can someone recovered from #COVID19 get sick again?
4. What happens when this #coronavirus mutates?

Antibody tests will help write the next chapters.

Cool pics from @USATODAY