Talk to General Physician on Interest, Information

Hello dear experts,

I’d like to know why

a) they would take a coronavirus swab from both your nose and your throat? Isn’t the virus kind of everywhere in the liquids of your respiratory system?

b) why is the nasal swab for coronavirus so deep? We’re supposed to keep the social distance of 1,5 m, which means that it should actually be more than enough to analyse a spit, a snot or just a swab from your tongue or from the beginning of your nostrils or at least just not that deep.

Thanks