The mathematician: This is how big the difference will be if everyone wears mouth guards

The more contagious British virus variant is now spreading in Sweden.

There is a risk that the mutation will become dominant and take over the virus strain in Sweden, says Tom Britton, professor of mathematics at Stockholm University.

Then the R-number, a measure of how many people a sick person infects, can go up and pass 1.

In that case, Sweden needs to introduce new measures to curb the infection, according to the mathematics professor.

In the clip above, Tom Britton tells how the R-number would be affected if everyone started wearing mouth guards.