Science question: can you catch more than one variant at the same time?

[notevenat20]

There are all these variants of covid and in particular they talk about b117 outcompeting other variants by being more infectious. But this implies that you can only catch one variant at a time. Why would that be?

You could catch more than one at the same time. The "outcompeting" is in terms of the evolution of the virus. The figures below are made up, to try and explain it...

Suppose variant A has an R rate of 3, and variant 4 has an R rate of 5. The population starts with one case of each. This is how it spreads:

A - 1 person infected, B - 1 person infected
A - 4 people infected, B - 6 people infected
A - 13 people infected, B - 31 people infected
A - 40 people infected, B - 156 people infected
A - 121 people infected, B - 781 people infected

Variant B quickly becomes the dominant one, which means that people who are likely to be exposed to Covid (e.g. doctors and nurses) are more likely to encounter Variant B first. If they encounter Variant A soon after, they could still be infected with that at the same time. But it's more likely that by the time they encounter Variant A, they've already got some immunity from Variant B. So it becomes harder for Variant A to spread - while Variant B continues to spread easily.

so on an individual level Panda, you could get infected with both, but in all likelihood the experience you had of the second one would be much less significant - a sort of weaker second wave that you might not notice?
I suppose the only exception would be if for some reason your body was good at fighting virus1 but was using tools that don't work on virus2 for some reason.

A bit like catching two head colds just feels like a long cold whereas getting a secondary infection feels different?

There have been rare but proven cases of people being infected w two variants at once (data from Brazil). The good news is that the effect doesnt seem to be cumulative, like it is w flu plus cv.

I am just not sure why it would be rare to catch two variants. People who go to large events where they are mingling with many others for example.

It really depends on how similar the variants are; and whether they are similar enough that immunity from one gives a protective effect against the other, or if the differences are such that the second variant escapes.