- Why do infectious pathogens like coronavirus not end up infecting 100% of people? Marc Lipsitch claims this is because enough of the population becomes immune at a certain point, creating “walls” through which the pathogen cannot transmit. Where is the study that shows this is the explanation? Because the other possibility is that the estimates that “20% of the world was infected with 2009 H1N1” were taken too early (the pathogen was still spreading) or had limitations in some other way. Edit 3/12: Per https://medium.com/@tomaspueyo/coronavirus-act-today-or-people-will-die-f4d3d9cd99ca, this has implications: if we lift social distancing measures in x time, will cases just reappear? This is suggested by Spanish flu, and China being able to limit cases now but lifting social distancing soon will test this. :Edit 3/12.
- My friend told me hospitals will lack enough ventilators to provide breathing support; these ventilators may also be bulky and expensive. What happened to the portable, cheap ventilators called for in the [Johns Hopkins Center for Health Security report on technologies for global catastrophic biorisks](https://www.dropbox.com/s/5h3r7e9m0zrujgl/181009-gcbr-tech-report.pdf?dl=0)? For example, what happened to the [OneBreath ventilator](https://www.popsci.com/diy/article/2010-05/invention-awards-breathing-easy/)? Maybe that could be deployed now.
- According to Marc Lipsitch, on average it takes “three weeks to die from infection” from coronavirus. I assume this number is calculated only from those who have died? (This makes it less relevant to someone who does not know, in advance, whether they will die.) Also, how was the infection date measured, given that coronavirus is often asymptomatic? This is relevant for knowing how urgently one should fly home to see one’s elderly relatives if they start showing symptoms. Edit 3/12: https://github.com/midas-network/COVID-19/tree/master/parameter_estimates/2019_novel_coronavirus#time-from-symptom-onset-to-death. :End edit.
- What is the status of the coronavirus diagnostic from the CDC? How about those from other developers, e.g. SHERLOCK out of the Broad? Is SHERLOCK field-ready and better for this coronavirus situation?
Let’s say two friends are considering whether to hang out. If they check that neither of them have symptoms, is it safe to meet up? (This is not to say preemptive social distancing measures like closing down public gatherings are not useful; clearly they are, because even symptomatic people might come to those.)
- Elderly people are dying in higher numbers of coronavirus. This also seems to be true of flu and other potentially unrelated problems like air pollution. I never see this in my life because I’m not in the hospital and I don’t know many elderly people. What is the pathology in these diseases, i.e. how does death happen?
- Less important: I heard there are studies showing a bad health outcome if exposed to a high dose of virus, but a good outcome if exposed to a low dose. I don’t remember which virus, which organism (animal?), etc. Where are these studies? What is the implication, if any, for coronavirus? (For example, should we think of increased risk from being in crowded places as being explained by lots of virus particle from lots of people, i.e. high dose? This is different from how I usually picture it: a crowded place means more sick people.)
- How many tests did South Korea actually do when people say “they did a lot of tests”? Check https://ourworldindata.org/coronavirus.