A note on viral load which seems to be causing some confusion.
I wish I could draw a lifecycle type diagram here.... but heyho.
Viral dose- the amount of virus which you are exposed to (in your airways) at the point it enters and you become infected.
Viral load- after infected with the initial viral dose, it hijacks your cells and you start replicating and producing virus inside your body. This is the viral load.
Shedding- how much you’re putting out to others e.g. aerosols and droplets, fomites.
Scientists often use the term “viral load” interchangeably to describe the amount a patient has inside them or the amount they’re shedding.
The new variant does not appear to cause people to shed more virus (sometimes, confusingly called a viral load).
The new variant is mutated in the receptor binding domain (tip of the spikes) making it more “sticky” and able to get into your airways through a “door” called the ACE2 receptor.
That has been shown very clearly in the lab in a way which everyone is very confident plays out in real life.
This means we do know that the viral dose needed to become infected is lower for this new variant. You just don’t need as many particles to arrive at your airways to become infected, because the new variant is much more efficient at doing this.
We don’t know (waiting on some particular studies) if, once inside your cells, the virus begins to replicate more readily and increase your viral load ( this time, taken to mean the amount of virus a patient has in their body)
Higher viral doses are associated with worse symptoms and worse outcomes.
What’s worth saying with regard to the new variant versus the old variant and viral dose, is that it isn’t yet known, it’s very complicated and initial viral dose is only one factor in disease severity and patient outcome.