Chemotherapy drugs can have a temporal effect on the bone marrow and may so cause a reduction in the red blood cells, white blood cells and platelets. If there is a reduction of these cells, the body is easily bruised and bleeding will take longer to stop. White blood cells fight infections and so by a drop in the count of these cells, the body will be less able to fight any infection. Symptoms as headaches, muscle pain, sore throat, a cough, feeling cold and problems in passing urine may be an indication of an infection. It is very important that the physician is promptly informed if an infection is suspected since this can be very serious. It is important that the blood cell count is checked regularly and if it is found to be low, appropriate medications may be prescribed.

The patient must do his part to fight infections. He/she needs to take extra care for his hygiene. This is because germs that can cause an infection can be found everywhere and if the patient has a low white blood count they can easily procure an infection. Hands should be appropriately and regularly washed before and after eating, before preparing food and particularly after visiting the toilet. Door knobs may also contain a large number of germs. Extra care need also to be taken when using instruments, since germs my enter from the cut. Food should be appropriately cooked and raw food should not be eaten.
Special attention needs to be taken when public places are visited and particularly in crowded places. When there are a large number of people germs can easily travel from one person to another. 

Mesothelioma sufferers have a weakened immune system and so they may need a vaccine.