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."
https://blogs.sciencemag.org/pipeline/archives/2020/07/07/more-on-t-cells-antibody-levels-and-our-ignorance
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/status/1278357445023109121
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
This makes perfect sense, illustrates some of Neven's points, and is a point I have also been making. I do believe there is a substantial % of the population where the innate immune response neutralizes the virus hence no symptoms NOR asymptomatic transmission NOR antibody response. Just no response at all (besides virus dead).
This would explain why NYC is at seemingly herd immunity with 35% infected. If 10%+ of the population has innate immunity, NYC is already at the same % of infected / immune it got in three waves of Spanish Flu (45%+).
Innate immunity could also vary depending on ethnic composition / healthiness / etc. Perhaps this is why CDMX and NYC are getting hit so hard. And this also explains why Sweden is getting severely impacted and not Norway and Finland (besides the lockdown difference, Sweden has enormous immigrant ghettos where the spread has been occurring).
With that, I think we can actually begin to develop an agreeable hypothesis for those in this thread.
1) COVID is real. lol
2) COVID disproportionately effects the elderly and those with pre-existing conditions, esp obesity
3) COVID disproportionately impacts different blood types, skin colors, and income levels
4) COVID has a mild impact on healthy populations
5) COVID has no impact on some healthy populations / they are innately immune (10%+++ depending on region)
6) COVID is seasonally sensitive, with both transmission and fatalities rising during wintertime
7) COVID seems to burn out after .1% to .3% of a total population has died in larger regions (100K+ population), while local mortality rates can vary from almost 0 to 1%, depending on a region's population pyramid re: factors 2-5 and seasonality in factor 6.
8 ) With geographic spread essentially unlimited and NHEM winter imminently upon us (we are two months out from when falling sunlight begins to become meaningful and pop-wide Vit D production falls off a cliff above 25 degrees N), it is likely COVID is going to spread uncontrollably in the NHEM as transmission and death rates start rising come September. By April and May next year, COVID will be mostly eliminated through either herd immunity, or herd immunity in sync with a vaccine. Fatalities and impact this winter will be most focused on those areas hit least hard during the spring-summertime waves (paradoxically this means China may actually be at greatest overall risk of any country even if their current #s are comically low).