Some of the HIV-inflicted are carrying the virus for months upon months. Their immune system can’t eliminate the virus entirely, and so it has innumerable oppor

Some of the HIV-inflicted are carrying the virus for months upon months. Their immune system can’t eliminate the virus entirely, and so it has innumerable opportunities to mutate into a more infectious form. It has much less opportunity to do so in those who can clear it out in a few weeks, and much, much less opportunity in the vaccinated.