This mechanism was observed with, I believe, viruses like Marburg or Ebola, that tend(ed) to kill within hours or (few) days.
Covid-19 really does a pretty good job in this regard already: being infectious before symptoms begin, and taking weeks to either kill or resolve.
Very little would be gained, relatively, from the sort of changes Ebola & Marburg went through.
We also need to consider how people react to being infected with Covid-19: With the disease being universally known, what are the chances of a typical patient infecting additional people if you add another week at the back end of their infection? Chances are, they are in isolation from the second week on. Any contacts they keep having (with family, housemates, or medical personnel, say) will either be infected by week 3, or proven to be rather skilful at avoiding infection.
Covid-19 really does a pretty good job in this regard already: being infectious before symptoms begin, and taking weeks to either kill or resolve.
Very little would be gained, relatively, from the sort of changes Ebola & Marburg went through.
We also need to consider how people react to being infected with Covid-19: With the disease being universally known, what are the chances of a typical patient infecting additional people if you add another week at the back end of their infection? Chances are, they are in isolation from the second week on. Any contacts they keep having (with family, housemates, or medical personnel, say) will either be infected by week 3, or proven to be rather skilful at avoiding infection.