This is a YouTube video titled "When Is COVID-19 Most Contagious?" containing a detailed explanation from a single speaker about the nuances of asymptomatic and pre-symptomatic spread of COVID-19, viral load dynamics, and mortality rates, recorded in May 2020 during the early phase of the pandemic.
It's a difficult nuanced concept, this asymptomatic spread. So I think a lot of people think there's like zombies out there that are not symptomatic, that are spreading all over. And I do think truly asymptomatic spread is less usual. What we have here is a period, what we call pre-symptomatic phase that probably lasts two days. Influenza may be a day where you don't have any symptoms or you're pre-apparent and the viral loads in this illness are highest at the onset and then fall. SARS-CoV-1 was different. It was high and then it got higher with illness. But this actually at the onset, and so you're most contagious when you have the highest viral loads. And as you mentioned, there is a period where before you might have onset of symptoms, you could be potentially contagious to others. Enhance the rationale for the universal masking. Now in terms of mortality, I mean, you mentioned, we're seeing mortality rates all over the board a little bit. US, if you look overall, it's about 3 to 4%. It is not across the board equally though. This is a disease that is not treating our elderly and elderly with comorbid conditions, it's different, right? So, almost, I think in the states, 80% of the deaths are in people over 65. Most of those have comorbid conditions. Obviously, we've seen young people, as you mentioned, in, ICUs. Most of those also will have a comorbid condition.
