I asked:
have you seen any studies on COVID immunity durability and enhancement?
No, but here is some material on the difficulty of testing for
COVID infection and COVID exposure
Article by lowe in science blogs:
“from The Lancet on a large study in Spain. Testing tens of thousands of people across the country continues to show that (on average) only about 5% of the population is seropositive (that is, has antibodies to the virus).”
“at least one-third of the people who now test positive never showed any symptoms at all. ”
“we are still not sure if this means that 95% of the Spanish population has never been exposed to the virus, because we don’t know how many people might have cleared it without raising enough of an antibody response to still be detectable. ”
” 40% of asymptomatic patients went completely seronegative during their convalescence.”
“At a minimum, you’d want to know antibody levels over time, T-cell response over time, and (importantly) what a protective profile looks like for both of those. We barely have insight into any of this: the large-scale data are just a snapshot of antibody levels, and that’s not enough.”
“We could have people who look vulnerable but aren’t – perhaps they show no antibodies, but still have a protective T-cell response. Or we could have people who look like they might be protected, but aren’t – perhaps they showed an antibody response many weeks ago that has now declined, and they don’t have protective levels of T-cells to back them up.”
This references a twitter thread by Bleicher:
” Virus must get through mucous membranes, a physical barrier. 2. Innate immunity can destroy virus before it starts. 3. Neutralizing antibodies and memory B cells protect against future infection 4. T cells destroy infected cells”
https://twitter.com/pbleic/sta
Note that it is much more difficult to test for T-cell and B-cell response than it is to test for antibodies. Very few results have been published for T and B cell response compared to the antibody serological results.
sidd