Medical question: is there a test for COVID-19 immunity?

[Girard442]

Or could there be one soon? There is lots of speculation about people having had the disease with mild or no symptoms. Maybe the immune walk among us.

[intrepidity]

1. I'd be surprised if there weren't antisera already

But it would require a blood sample to test.

ELIZA - enzyme linked immunoassay is the old school method, not sure what today's method would be

ETA: yep, plenty of tools, eg:

https://www.prosci-inc.com/covid-19/

https://www.assaygenie.com/sarscov2-covid19-detection-methods

[a la izquierda]

2. This is unrelated to COVID, but several years back there was a great documentary..

about a genetic mutation that allows some Europeans (or people of European descent I imagine) to be immune to HIV. The gene is called CCR5-Delta and the documentary is called "Mystery of the Black Death." It's fascinating as hell.

[Bernardo de La Paz]

3. 1) It mutates, 2) Some have tested positive after "cured", 3) This is a NOVEL virus: no immunity.

If you have mild symptoms you were never immune.
If you got the disease (thus can transmit it) and had no symptoms you were never immune.

This is a NOVEL virus, the "novel corona virus". The medical term NOVEL means no existing immunities in humans.

[mahina]

6. Like when the Hawaiians were reduced to 10%

Off the population because they had no resistance to Western diseases.

I’m usually not in the doom chorus at DU and this virus has nothing like that mortality, but that happened.

[intrepidity]

9. The idea is, after infection, your body should have a record

The infection will cause your body to mount an immune response, which will result in your body producing antibodies to the virus.

Drawing blood and finding those antibodies is the test showing you have previously been exposed.

Detection is done using antibodies-against-antibodies. Those tools are currently available, I'm fairly certain.

There's often confusion because scientists use the same tools that our bodies use -- antibodies.

Our bodies use them to detect foreign invaders and to signal to our immune system. We have adopted the use of those same tools to detect and signal presence of "things" (antibodies can be made against viruses, proteins, cells, even other antibodies). We also try to make antibodies that can directly interfere with processes, such as virus binding etc (therapeutic antibody).

Antibodies are nature's Swiss army knife.

[Bernardo de La Paz]

10. Yes. The OP was writing as there are some pre-immune. Or not clearly at all. Or confused what immuni

Or confused about what immunity means.

OP seems to think that getting a mild case and surviving means that they were immune from before and is hoping that pre-immune people could be found (and perhaps relieved of worry?).

[intrepidity]

11. I took that post to mean

Whether there was a test to detect whether someone had been exposed but didn't become symptomatic.

The answer should be yes. If you have antibodies to the virus, it means you have been exposed.

[Girard442]

12. If you get the disease and survive, you'll be immune.

Even if you get only mild symptoms and fully recover, you’d be immune.

How long you’d be immune is an open question right now.

I suppose there could be people resistant to COVID without ever being exposed to it, but those people would be serious outliers and I doubt the phenomenon would be useful to anyone but them.

[coti]

13. Hence the term, "herd immunity"

Some are just mistaking terms in the OP.

[Girard442]

16. I herd that too.

[Bernardo de La Paz]

19. Yup, I wrote that

If you have mild symptoms you were never immune.
If you got the disease (thus can transmit it) and had no symptoms you were never immune.

I hope it is clear that by "were never immune" (note past tense) I mean that you only become immune after getting the disease and surviving (or getting a vaccine shot).

And I also wrote in this thread

Note: you only have antibodies to a novel virus if you got the disease and survived.

[coti]

14. Immunity can and most often occurs post-exposure.

Even by vaccine.

[Girard442]

17. Actually you become immune during the infection.

If you don’t, the virus rages through your body unchecked by your immune system and you die.

[coti]

18. But exposure is the first moment you encounter it, right? nt

[Girard442]

20. Exactly. First you are exposed, then you become infected, then you become immune, and then...

...you recover, (we hope).

[Bernardo de La Paz]

4. Dutch researchers first to find Covid-19 antibodies

https://nltimes.nl/2020/03/14/dutch-researchers-first-find-covid-19-antibodies-report

Note: you only have antibodies to a novel virus if you got the disease and survived.

[intrepidity]

7. Note: this research is looking for a therapeutic antibody

That is, one that blocks the virus.

Other antibodies are available for detection purposes, see links in my post above.

Antibodies play many roles in the body and the lab.

[nilram]

21. "...and the ability for people to test themselves at home for the presence of the virus."

From the first paragraph. Cool that there are other antibodies to test for, too.

[Nonhlanhla]

5. I think I read somewhere

that some researchers are working on a serum test so that they can later use to find out who had COVID-19 without knowing it. That way they can start to figure out the real death rate etc.

[Hearthrob]

8. But viruses keep changing their clothes almost yearly and we need new vaccines

Slippery little suckers.

[coti]

15. I'm actually wondering if I got it in January.

Our family got something with a painful sore throat, which constricted the throat and made breathing difficult, only slightly runny nose and a fever that wouldn't go away for a week or more back in mid-January. Dry cough. It very briefly attempted to move into my lungs and I coughed up some really nasty stuff, but my body kicked it out.