-
Not quite.
Infection invariably leads to some form of immune response.
However, if small viral load- Still has an immune response but you may not raise (sufficient quants of) antibodies (to be tested) due to the innate immune system. (And if you’re immune/vaccinated the antibodies from memory cells increase the efficacy of the innate immune system whilst simultaneously switching on the adaptive immune system faster).
Again, however, from what I’ve read- we are using rt-PCR to confirm diagnosis (https://www.who.int/docs/default-source/coronaviruse/protocol-v2-1.pdf?sfvrsn=a9ef618c_2) . This is a sequence led assay rather than antibody testing. There are attempts to make an ab testing but I don’t know if any are successful.
The rates of false negatives are reported as high as 3%, with many below this.
This is possibly due to a low viral load at initial presentation, or failure of the pcr probes, or something I’ve forgotten from biochem.
WRT to transmission, asymptomatic, I’d hazard a guess that you’re holding enough viral load to spread, but without the symptoms associated with a immune response.The Americans are using a different assay.
You are reading a single comment by @deleted and its replies.
Click here to read the full conversation.
deleted
As far as I'm aware tests for viruses look for your bodies immune response to specific viruses. Therefore it is possible to be asymptomatic but still contagious and not test positive. Which is why people who may have been exposed are effectively asked to quarantine themselves.
But IANAD so could be wrong and it's been years since I studied this stuff.