CLIA - Tests Total Ab (IgM + IgG)
CMIA - Tests IgG only
If anybody undergoes RAT, preferably go through both these tests. Most labs will give you an option for both. They would generally check CLIA first - if that's negative - you have no ABs. If CLIA is +ve, they will recheck the sample of IgG via CMIA. If IgG is positive, that means you have a past infection (anywhere between 2 weeks - some months old), and you *might not* be shedding the virus anymore (can't be sure though). It does mean that you have delayed ABs in your blood, and you are most likely immune to the disease for short term.
If CLIA is +ve, and CMIA is -ve, that means you have IgM in your blood, which signifies recent infection, and you should get a RTPCR done for final diagnosis.
Central govt has mandated that now RTPCR can be done without a prescription, but some states like UP (MOTHERf**kER YOGI) have not implemented it. Infact, we don't even have home quarantine in UP. Only institutional quarantine. Beat that !