@rajrealestate 1) We mount B & T cell responses to infections. Seroprevalence studies look for antibodies made by B cells. They don’t measure T cell response. They probably also miss low level exposure that didn’t generate enough antibody titer to meet whatever cut-off they picked for positive
@rajrealestate 2) Many studies now show that T cells reactive to SARS CoV-2 are present in blood collected way before pandemic. So there is likely some cross reactive immunity from prior corona virus infections. Corona viruses are very common. SARS CoV-2 is one type, but related.
@rajrealestate 3) T cells reactive to SARS CoV-2 have also been found much more often in close contacts of COVID patients who have no antibodies by serology. This suggests antibodies are not generated in all people who are exposed COVID.
@rajrealestate 4) The course of the pandemic in Wuhan, Lombardy, Spain, NY, etc suggests more poeple are not susceptible than seroprevalence indicates.
@rajrealestate Time will tell. My field is cancer of the immune system, and on the cells that make antibodies. I know these cells don’t die easy. Once they catch the scent they won’t let it go. They can hide in low numbers and not make antibodies till needed. The level tells us little. @Rfonsi1
@rajrealestate @Rfonsi1 Here is a thread on related topic that discusses these issues more.
