As someone that finds the size and scale of things fascinating, this research from PNAS stands out. It's titled “The total number and mass of SARS-CoV-2 virions”.
According to the research: “…each infected person carries an estimated 1 billion to 100 billion virions (individual virus particles) during peak infection, their total mass is no more than 0.1 mg. This curiously implies that all SARS-CoV-2 virions currently in all human hosts have a mass of between 100g and 10 kg. (about the weight of a bar of soap to about the weight of a toddler). Multiply their math out to 1 billion infected persons and the total weight is something around 200 pounds. In other words, all of the virions (individual virus particles) in all of the human hosts of that pandemic would weigh something like a few hundred pounds.
The size, scale, and weight of certain things are remarkable.