Safety

Bacterial immunotherapy has an excellent safety profile. It results in the activation of the immune system which typically results in flu like symptoms. 

BCG specific side effects in the treatment of bladder cancer are common. These side effects usually settle within a 48 hour period and require little more than paracetamol as treatment. Patients receiving BCG treatment can develop fevers and can, albeit rarely, suffer from more severe symptoms resulting from the microbial infection. These symptoms can, in the vast majority of cases, be treated effectively.

Similarly, OK-432 has also been found to be safe and result in relatively minor side effects. 

Bacterial immunotherapy results in a temporary (and local) activation of the immune system and is not expected to have a long term negative impact on quality of life.