Can someone more familiar with the virology comment on the meaning of this statistic? I keep hearing it, but I don't really know how to interpret it. Delta's obviously more infections than the original strain, but could one simply have a virus that "weighs more" than another virus, without being more contagious, and have it have 1000x more "viral mass" or "viral load?"

How should this stat be interpreted epidemiologically? Should we care more about R0 than viral load?