Mon, 15 June - Anything Can happen, page-107

It´s about the viral load. asymptomatics show low viral load, and therefore symptoms such as fever don´t show up. Having a low viral load means the concentration of the virus in your body is low enough and therefore, in simple terms, you don´t have much in you to transmit to others, or even to deeply get affected yourself, as your immune system constantly handles low concentrations of different virus. That´s the reason as well why the principal focus of the virus around the world were nursing homes, hospitals and public transport, where big loads of virus are concentrated in small crowded rooms, and why there haven´t been outbreaks in places like, for example, Taiwan and Hong Kong, where they take people´s temperatures before getting inside buildings. One way to understand the concept of viral loads is to investigate the advance of modern medicine towards HIV and how people under treatment that have lowered the viral load under certain levels can live normal lives, and even not be contagious anymore. I never understood why they made all that fuss about asymptomatics to start with but well, one of the many things I´ve never understood. Hope it helps