A live cell biology approach to scrutinize transmission of the P22 temperate phage throughout a Salmonella Typhimurium population at single cell resolution revealed that this phage is able to disseminate immunity conferring factors in a way that allows the emergence of transiently resistant subpopulations of host cells. The fostering and subsequent consumption of such subpopulations could represent a strategy by which phages manage to sustain an active infection in co-existence with their host.