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Can you test covid positive twice?

I tested positive for COVID 19 back in November, then developed antibodies strongly, and now have tested positive...again?

It could be a false positive, but I wanted to know if it's possible to test positive while having antibodies. How long do antibodies take to fight if you are re-infected with covid?

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Yes you can.
Reply 2
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Anonymous #1
OP
Can you explain the science though? My antibodies have not waned over time.

So in my blood, if the antibodies are there and the coronavirus re-enters, I assume my antibodies would destroy them before they spread. So how can I test positive again?

I know people a minority can test positive again (I remember someone in HK did) but wasn't that because their antibodies declined.
Original post by Anonymous
Can you explain the science though? My antibodies have not waned over time.

So in my blood, if the antibodies are there and the coronavirus re-enters, I assume my antibodies would destroy them before they spread. So how can I test positive again?

I know people a minority can test positive again (I remember someone in HK did) but wasn't that because their antibodies declined.

No I can't, idk the science behind it.
Reply 4
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Anonymous #1
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Can I be a carrier even after being covid positive?
You don't become immune to covid after you test positive
Reply 6
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Anonymous #1
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Original post by rxyaltyx
You don't become immune to covid after you test positive

...even after getting antibodies? If what you're saying is true then vaccines have no point.
Reply 7
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Pugglet
20
I tested positive twice (one in September and then in November)

However they do advise you do not retest until 90 days after a positive test result.
Reply 8
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Original post by Pugglet
I tested positive twice (one in September and then in November)

However they do advise you do not retest until 90 days after a positive test result.

Yes, that is a possibility if you didn't develop antibodies or your antibody levels waned over time.

However, mine didn't. Which is why I'm very confused. Could anyone explain what's happening?
Original post by Anonymous
I tested positive for COVID 19 back in November, then developed antibodies strongly, and now have tested positive...again?

It could be a false positive, but I wanted to know if it's possible to test positive while having antibodies. How long do antibodies take to fight if you are re-infected with covid?


Reinfection is currently an area of analysis. It's not clear exactly if & under what conditions reinfection happens. Their has been some reports of reinfection in a very small percentage of people, however the good news is (so far) where reinfection has occurred the immune response has also kicked in and I dont believe their have been any hospitalisations of it so far. Additionally their is growing confidence in the bodies immune response to last for a long period of time, so far people infected March last year are continuing to display antibodies, and this disease is similar to SARS where antibodies lasted several years.

I am not a virologist or healthcare expert, just how I have interpreted the info Ive seen
Original post by Anonymous
Yes, that is a possibility if you didn't develop antibodies or your antibody levels waned over time.

However, mine didn't. Which is why I'm very confused. Could anyone explain what's happening?


My first test was a false positive.

You can have the antibodies and still carry the virus and therefore test positive.
Original post by Pugglet
My first test was a false positive.

You can have the antibodies and still carry the virus and therefore test positive.

I'm sorry for bugging you further then what is the point of vaccines and herd immunity, if people will test positive and can still be a carrier after developing immunity?
Original post by mnot
Reinfection is currently an area of analysis. It's not clear exactly if & under what conditions reinfection happens. Their has been some reports of reinfection in a very small percentage of people, however the good news is (so far) where reinfection has occurred the immune response has also kicked in and I dont believe their have been any hospitalisations of it so far. Additionally their is growing confidence in the bodies immune response to last for a long period of time, so far people infected March last year are continuing to display antibodies, and this disease is similar to SARS where antibodies lasted several years.

I am not a virologist or healthcare expert, just how I have interpreted the info Ive seen

Thank you! Yes, I know that re-infection is a possibility in a small minority, but can you be "re-infected" while possessing antibodies at the same time...
Original post by Anonymous
I'm sorry for bugging you further then what is the point of vaccines and herd immunity, if people will test positive and can still be a carrier after developing immunity?


It will lessen the effects of the virus if you do catch it. You are less likely to end up severely ill and on a ventilator.
Original post by Anonymous
Thank you! Yes, I know that re-infection is a possibility in a small minority, but can you be "re-infected" while possessing antibodies at the same time...

Im not a virologosit but I would believe a small amount of the virus enters your body, it then invades your cells and starts to replicate. At which point the your bodies immune system will recognise the virus as it recognises it from previous infection so the antibodies come and fight off the virus. It's not like once you've had an antibody the virus cant enter your bodies cells it's just your bodies immune system has developed the ingredients to fight the virus so it tackles it very rapidly when it re-enters and in most cases your body will fight off the virus before you ever reach the re-infectious stage (or before you've ever had a symptom)
(edited 3 years ago)
I have no idea about the antibodies but i swear they did a study using nurses working with COVID patients who obviously ended up getting it and 80% were protected for up to 5 months or something after infection which still leaves 20% (i think it was a little less than that). I think the vaccine works differently as its the coating or something so you are not actually being infected with it, it just recognises it. But this is an area they are looking into. I think out of the 20% the majority had either no symptoms to little symptoms presumably because they had already had it. Sorry i dont know more i just remember seeing that on the news a little while ago.
Original post by mnot
Im not a virologosit but I would believe a small amount of the virus enters your body, it then invades your cells and starts to replicate. At which point the your bodies immune system will recognise the virus as it recognises it from previous infection so the antibodies come and fight off the virus. It's not like once you've had an antibody the virus cant enter your bodies cells it's just your bodies immune system has developed the ingredients to fight the virus so it tackles it very rapidly when it re-enters and in most cases your body will fight off the virus before you ever reach the re-infectious stage (or before you've ever had a symptom)

Exactly what I was looking for, so thank you very much.

So I imagine by the antibodies realise the virus' presence, the virus will have replicated and invaded cells to a certain extent, and this extent can be above the minimum threshold to be covid positive? Makes much more sense.

Perhaps that's why Mr. Johnson went into self-isolation again, despite having tested positive already.
Original post by something_orphic
I have no idea about the antibodies but i swear they did a study using nurses working with COVID patients who obviously ended up getting it and 80% were protected for up to 5 months or something after infection which still leaves 20% (i think it was a little less than that). I think the vaccine works differently as its the coating or something so you are not actually being infected with it, it just recognises it. But this is an area they are looking into. I think out of the 20% the majority had either no symptoms to little symptoms presumably because they had already had it. Sorry i dont know more i just remember seeing that on the news a little while ago.

They did a survey of healthcare workers between 1st & 2nd waves. Out of nearly 1000 infected in 1st wave it had 0% reinfection, and out of 10,000 non-infected in first wave around 14% got infected in the second wave.
https://www.journalofinfection.com/action/showPdf?pii=S0163-4453%2820%2930781-7
Original post by Anonymous
Can you explain the science though? My antibodies have not waned over time.

How do you know?

The immune system, and more importantly the ways bacteria and viruses evade the immune system, is highly complex and frankly no one knows the details of how covid might interact with it or evade it. This idea that antibodies bind to virus and kill it is far too simple. Antibodies are not necessarily protective at all (though they probably are in covid).

The main reasons to test positive a second time are false positives, and residual positive tests after an initial true positive. Its thought people probably can have two genuine positive tests, but it doesn't seem to be common at all.

Original post by Anonymous
I'm sorry for bugging you further then what is the point of vaccines and herd immunity, if people will test positive and can still be a carrier after developing immunity?

Well, firstly two positive tests seems to be rare.

Secondly, you'd hope that that second illness may be a lot more mild than what the first might have been.

Thirdly, note that the vaccine is created differently to natural immunity. You seem to be lumping the two together. There are plenty of examples of vaccines being a lot more effective than natural immunity. And we do of course know that current vaccines are not 100% effective, so you definitely can test positive following a vaccine. Its just that the chance is a lot lower and again, hopefully it'd be a much more mild illness.
(edited 3 years ago)
Original post by nexttime
How do you know?

The immune system, and more importantly the ways bacteria and viruses evade the immune system, is highly complex and frankly no one knows the details of how covid might interact with it or evade it. This idea that antibodies bind to virus and kill it is far too simple. Antibodies are not necessarily protective at all (though they probably are in covid).

The main reasons to test positive a second time are false positives, and residual positive tests after an initial true positive. Its thought people probably can have two genuine positive tests, but it doesn't seem to be common at all.


I agree, antibodies binding to antigen surfaces are perhaps too simplistic a model.. but the reason I know they haven't waned over time is because I've had quantitative levels of my antibody checked ever month since, and the levels have remained more or less the same.

Original post by nexttime


Well, firstly two positive tests seems to be rare.

Secondly, you'd hope that that second illness may be a lot more mild than what the first might have been.

Thirdly, note that the vaccine is created differently to natural immunity. You seem to be lumping the two together. There are plenty of examples of vaccines being a lot more effective than natural immunity. And we do of course know that current vaccines are not 100% effective, so you definitely can test positive following a vaccine. Its just that the chance is a lot lower and again, hopefully it'd be a much more mild illness.


I know vaccines trigger the immune response differently, but I don't think the antibodies are structurally in any way different to what you get from natural immunity? B-cells and T-cells are still stimulated whether you are naturally infected or not. Yes, the extent of antibody production will most certainly vary (I think for COVID natural infection > better immunity > vaccines).

My question was why, despite having the antibodies, after 3 months I am testing positive again. The only conclusion I can come to is that I will have come into contact with a COVID positive induvial, the virus must have entered my body and my antibodies have still not finished killing the virus

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