You can theoretically spread some viruses about one day before you show symptoms, but is there any evidence that this is a significant vector for any virus? It makes sense to me that it would still be hard to spread, since if you aren't showing symptoms, you aren't going to be sneezing or coughing yet. Sure, if you french kissed someone, but otherwise?BlackGoldAg2011 said:your first paragraph is categorically false. there is evidence for pre-symtomatic going back to non-chinese studies as early as January/February of 2020 (https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30314-5/fulltext). A lot of this got confuse though as there were also studies that started coming out showing asymptomatic spread as rare. And I don't remember who was at fault but there was imprecise language used to differentiate the two which led to confusion and argument. Also there are multiple other viruses that you can be contagious in the incubation period. Flu you can be contagious up to a full day before symptoms, rotavirus can be contagious for several days before symptoms just to name a few. The only thing that makes Covid unique in that sense is that in general it is contagious longer before symptoms and the incubation period can be longer.agforlife97 said:
"Pre-symptomatic spread?" There's no evidence for this either, and that's not how other viruses work. In many other viruses, you can still spread the disease for a short period after you recover, but in a pandemic that's a lot easier to manage.
This, and things like the myth of "spreading from contaminated surfaces", children as vectors, and many other things in this pandemic have really given the epidemiological community a black eye, and they may never recover from it.
I see broad failures of public policy here, and the desire for autocratic powers in all level of government is very disturbing. Glad this is over.
I will however give some agreement to the "spreading of myths" part. While the scientists/doctors doing the research and writing the papers are usually not to blame (though sometimes they are) the communication on all of this has been terrible. A perfect example is vaccines. Early on, the general message being spread was "if you are vaccinated you can still spread it", but if you actually dug into the citations and research behind the message, what the original message from the technical folks said was that "we don't have hard evidence that you can't spread it post vaccination and we didn't set up our trials to be able to test that, so we can't say for sure. Also there is this other study in monkeys showing it may still be reasonably possible." Those responsible for communicating these kind of the messages utterly failed. It is fair to offer grace to the researchers doing their best to find answers to a novel virus in real time. "I don't know"s and changes to conclusions were to be expected, especially early on, but I have little to no grace for those responsible for communicating those answers, who, in an effort to so simplify the real answer, ended up lying to the public because the simple version lost so much that it no longer matched the truth.