Once youve had covid-19, do you have immunity to it?

[milestogo]

[dem4decades]

1. I saw some where a person was reinfected so I guess not.

[lame54]

2. Several who have been cleared...

Re tested positive

[defacto7]

3. It doesn't seem all the data is in. We should, but

there are cases of relapse and nothing official as to why.

[wishstar]

4. Jury's out with reports of people reinfected but Dr Fauci says they're not getting reinfected

at press conference, Dr. Fauci said absolutely that when people recover they do not get it again.

However reports keep coming out about re-infections but that may be in people who test positive, then negative due to faulty testing, and then positive again after a period of weeks has elapsed.

[dalton99a]

5. Can people who recover from a bout with coronavirus become infected again - and again? (NYT)

https://www.nytimes.com/2020/02/29/health/coronavirus-reinfection.html

They Recovered From the Coronavirus. Were They Infected Again?
In a few cases, patients again tested positive for the virus after they were no longer ill. But little is known about the virus, and it’s possible that testing flaws may be to blame.
By Apoorva Mandavilli
Feb. 29, 2020, 5:00 a.m. ET

...

“I’m not saying that reinfection can’t occur, will never occur, but in that short time it’s unlikely,” said Florian Krammer, a virologist at the Icahn School of Medicine at Mount Sinai in New York.

Even the mildest of infections should leave at least short-term immunity against the virus in the recovering patient, he said.

More likely, the “reinfected” patients still harbored low levels of the virus when they were discharged from the hospital, and testing failed to pick it up.

In four medical professionals exposed to the virus in Wuhan, China, the epicenter of the epidemic, a test that detects the viral genetic material remained positive five to 13 days after they were asymptomatic.

This does not necessarily mean that they were still able to infect others, however.

The PCR diagnostic test is highly sensitive and can amplify genetic material from even a single viral molecule. As such, the test could merely be picking up fragments of the virus.

PCR tests may detect remnants of the measles virus months after people who had the disease stop shedding infectious virus, Dr. Krammer said.

The other possibility is that the negative test was done poorly, or the samples were stored at a temperature at which the virus deteriorates. The throat swab may also simply miss the virus that is hiding elsewhere in the body.

“A virus test is positive if the virus was there on the swab in sufficient quantities at the time you swabbed the person,” said Marc Lipsitch, an epidemiologist at the Harvard T.H. Chan School of Public Health.

Dr. Lipsitch offered an analogy: a jam jar with mold on top. Scraping off the surface might give the impression that the jam is now mold-free, but in fact the jar may still contain mold that continues to grow.

[patricia92243]

9. Could they then be carriers but not infected themselves. Sort of

a typhoid Mary.

[csziggy]

17. I hope it is not like Equine Infectious Anemia (EIA) or Swamp Fever

When I was a kid, EIA had no tests, no vaccine, no real treatment. Horses got it, had multiple bouts of illness and then declined drastically until they either died or the owners put them down. A horse I cared for in the 1960s died of EIA after a long lingering decline.

Some horses could live with the virus, but became carriers. EIA is transmitted mainly through blood sucking insects so if a fly or mosquito bit an infected horse, the horses it bit afterwards were likely infected.

In 1970 Dr. Leroy Coggins developed a test for the antibodies of EIA. Although many horse owners fought it, the way to control the disease was to isolate any horse that test,m out of the flight range of any blood sucking insects. Implementation of this method went state by state. Horse owners from neighboring states objected to the enforcement when they went to a state that had those requirements. For instance, Florida passed the testing and quarantine rules years before Georgia. Since I was involved in putting on horse shows in Florida we got a lot of flack from horse owners from Georgia where the tests were not required when we turned away their horses.

A note on this - the enforcement line in Florida for agricultural products is at the Suwannee River. I live west of that line, so enforcement is not as thoroughly enforced in my area as it is east and south of here.

There is no readily available vaccine for EIA -"No specific treatment or safe and effective vaccine is available." (See Merck reference below). There is a vaccine that has been used in China but it has not been used widely in the USA as yet. (https://www.ncbi.nlm.nih.gov/pubmed/21499906)

If the coronavirus is similar to EIA we have a really bad problem. Until and if a vaccine is produced and widely used, the disease can spread and will not be controllable. While quarantine might work, people in most countries will not put up with that if they appear healthy and the world economy cannot sustain quarantining millions of people and keeping them from their work.

Sources:
https://www.merckvetmanual.com/generalized-conditions/equine-infectious-anemia/overview-of-equine-infectious-anemia
https://aaep.org/horsehealth/equine-infectious-anemia
https://www.aphis.usda.gov/aphis/ourfocus/animalhealth/nvap/NVAP-Reference-Guide/Equine/Equine-Infectious-Anemia

[unblock]

6. it's very likely that once you recover, you're essentially immune. however,

there is no test that really "proves" you've recovered. the tests might fail to pick up on a lingering low exposure that can later come back to make you appear sick a second time when really you had never fully recovered.

[uppityperson]

10. I've read reports of it lingering deep in lungs, So "recovery" may be actually only partial

[unblock]

11. yes, some in fact think the disease is biphasic

Last edited Tue Mar 3, 2020, 02:56 PM - Edit history (1)

essentially meaning a false recovery followed by a "relapse" may be a normal part of the progression of the illness.

[obamanut2012]

14. That actually happened to me last month with a bad virus

Not the flu, but it was almost as bad. I felt way better, on the mend, got cleared for work and the gym again. I was very careful with my energy, but about a week later I had a bad relapse, and had to take a few days off.

This also happens with some flu strains and an EBV flare up (my GF has the latter).

[GemDigger]

7. No.

[hlthe2b]

8. Very likely as immunity to other coronaviruses has been shown to develop and PERSIST.

It is not clear whether it would likewise be very long term, however, nor whether small mutations in strains could impact that, rendering a recovered patient susceptible to future infection.

As we get antibody tests to perform community-based serosurveys and epidemiological studies, we'll have more answers on that. Right now, the test looks for the presence of nucleic acid consistent with the virus having been present. Some of those with repeated PCR positive tests might be shedding INACTIVE virus and no longer be infected--especially in asymptomatic or recovered patients. We can't tell that as of yet. The full immune response likewise needs to be evaluated and will be in the near future.

Data from China is a starting point, but we have to do the studies here.

[safeinOhio]

12. If so, might a

vaccine take longer to develope?

[zackymilly]

13. Everytime I read a virus post, I reach for my hand sanitizer...

...and even rub it on my face and nose.
I didn't know they had so many different scents.
I'm on the strawberry scented bottle now.

[Rebl2]

15. Well if it

is like a cold, then I would guess you could get it again. You know how they have to change the flu shot every year, hopefully this virus doesn’t change every year.

[The empressof all]

16. Not a medical professional but here's what I think anyway...

We are never really immune to colds. Most of us get them many times during our lifetimes. The virus mutates slightly and infects the body again. My guess is it is probably similar to Covid 19. So if and when there is a vaccine for Covid 19, there may very well be a covid-20.

Hopefully, like we cope with seasonal colds we will over time develop more resistance and the virus will be less deadly.

[yonder]

18. +1. Agreed

People get colds all the time. I don't know why an infection with a similar virus of the same family would be different.

We haven't cured the common cold, why would this be different? Maybe with enough exposure to different forms we would develop a resistence — until it evolves and the cycle starts again.

My 2 cents.

[EmeraldCoaster]

20. CDC just upped death rate.

3.4 percent

[shanti]

21. You know

I haven't had a cold in years, like maybe 20 years. It's weird. *knock on wood*

[Wounded Bear]

19. Too soon to tell, I'm sure...

probably won't know that until they have more data.