How do I know if I already had Covid-19 and thus have the antibody for it?
- KnightSaber2000Lv 61 month agoFavorite Answer
anonymous is right.. when people talk about COVID-19 screening, they talk about 2 different things: the Nasal Swab test and the blood/antibody test.. the Nasal swab test (the nasopharyngeal swab with Reverse transcription polymerase chain reaction (RT-PCR)) is the main test for COVID-19 diagnosis.. the RT-PCR test kit is expensive and harder to produce but it will tell you for certain whether you have COVID-19 at any given moment..
the antibody test (blood or serum test) should tell you whether you have or once had COVID-19.. it is cheaper and easier to produce, and it is as expensive as urine pregnancy test UPT to tell if someone is pregnant or not.. but because there is a time delay between the symptoms and the detection, a person with COVID-19 maybe tested negative on the blood test but positive on the nasal-swab test - which is why blood/antibody tests are not reliable to diagnose COVID-19 in its early stage, and the CDC would recommend the Nasal swab test as the main method to diagnose COVID-19.. the result is faster on the nasal swab test because you are detecting the virus directly inside the airway, while the blood test, it is much slower because the blood test measures the immune response to the illness - and this could take days to have any significant result.. it is the difference of seeing a fire or assessing the fire-emergency response to the fire..
proper antibody test measures few things, the IgM antibody level and the IgG antibody level.. the IgM level rises slowly within the first few days of an infection and it would remain high for about 2 weeks before its level drops.. IgG starts much later and much slower within 4 weeks and they last a bit longer from few weeks to few months..
so antibody provide a good surveillance tool for COVID-19.. so if you have contracted COVID-19 last month, your IgM levels would be high but the IgG would be low.. and your swab test would be negative..
this is important, because many news media would report that a COVID-19 vaccine would not last long because the antibody levels would drop after few weeks or few months.. a vaccine (any vaccine) will produce a humeral immune response by increasing the levels of IgM and IgG but those levels will drop in few months to few years which is very much expected.. what the news media fail to report is that a vaccine (a good vaccine) produces cellular immunity with more memory T cells and memory B cells remembering and ready to fight the infection in the future.. and these T&B memory cells last years and decades..
a vaccine will NOT stop an infection from occurring, a good vaccine shortens and reduces the symptoms of an infection.. so instead of 2 weeks of deadly symptoms/complications of COVID-19, a COVID-19 vaccine may bring the symptoms to minimal that lasts few minutes to few hours.. that's a vaccine is all about..
- Anonymous1 month ago
Get a blood test that screens for antibodies.