Clariman wrote:BTW the antibody test is NOT supposed to identify the vaccine created antibodies. It only identifies one's own natural immune system antibodies. So for whatever reason I have none of the latter.
There are different types of antibody tests. Are you saying that the one you took was specifically targeting the antibodies against the N protein i.e. reacting to the shell (nucleocapsid) of SARS-CoV-2 as opposed to the spike?
I don't claim to be an expert but for what it's worth I have tried to read up extensively on this stuff to a level well beyond the popular press and I believe that I have enough scientific background to be able to understand at least to some level some of the info that I am reading although I confess that I still cannot begin to get my head around how gobs of goo (chemical substances) seem to be able to do computation to the level of a Turing machine but I digress.
My thoughts, for what they're worth, are...
On the possibility of actually being positive 12 days after first vaccine dose, that is not at all surprising. This is such a common occurrence that most studies seem to screen out infections within the first 14 or even 21 days after the first dose. You might already have been incubating prior to vaccination or have caught it in the few days after vaccination. You might even have caught it during your vaccination outing. For people who have been sheltering or been extremely cautious the journeys to and from, and the time in the vaccination centre, might have been the riskiest thing that they did that month in terms of potential exposure to an infected person.
On the antibody test then from what you've said above I assume it was an N-protein specific test and since the AZ vaccine is specifically stimulating S-protein antibodies it can't tell you anything at all about what the vaccine has now done for you. To me this now takes us to one of 2 places...
1 - As discussed by others already, the PCR test was a false positive in which case the negative antibody test is entirely consistent even in light of your vaccination.
2 - The PCR test was accurate in which case why was an N-protein antibody test negative?
Well, on (2) above I note that your antibody test was 2 months after the supposed infection. That doesn't seem a hugely long time but I do note that research on Covid-19 immune memory done by Professor Shane Crotty, I would say definitely a credible expert since this research was discussed by Dr Fauci in a US Senate hearing, found that after 6 months the difference between the levels of antibodies between individuals in the study with the best and worst immune memory was a factor of 100 i.e. the person with the lowest level of immune memory had 100 times lower retained antibody levels vs the best responders. It's also worth noting that the memory didn't decay that much so those people with low responses after 6 months didn't have great responses after 1 month either. So if you really were positive at the time of the PCR test maybe the explanation for the N antibody result is that you are somewhere near the bottom of the memory curve and your N-protein antibody levels were too low to be registered even after 2 months.
Chapter and verso on the above is in this somewhat long (54:24) video of an interview with Prof Crotty where the key bit re the above starts at time index 6:22 although for context it might be worth starting at 1:00 (or the beginning!) -
https://www.youtube.com/watch?v=6aOMs1loXN0Another possibility is that apparently N-specific antibody tests can have a higher false negative rate than S1/S2 antibody tests so your antibody test being a false negative might be another explanation.
A short article about the different antibody tests and the source of my suggestion above re false-negative test is here -
https://www.technologynetworks.com/diag ... ein-340327 - where it specifically says...
Recent studies have shown the N protein-based antibody assays could exhibit a higher false-negative rate compared with the S1 subunit
As I said at the beginning, I am not an expert, simply someone who has tried to get at least a slightly deeper level of background knowledge on this, but some of the above does seem at least potentially relevant to your situation.
- Julian
