Covid-19 patients are most infectious one day BEFORE symptoms appear, study reveals

Covid-19 patients are at their most infectious one day before they develop symptoms, a mathematical study reveals. Researchers used a computer model to process data on viral load — the amount of coronavirus a person is infected with — and how it decreases throughout infection. Previous studies have found viral load aligns with infectivity and also increases the likelihood of death, meaning an infected person with a high amount of the virus in their system is more infectious and also at greater risk of dying from Covid-19.