Pharmacy contractors are advised to exercise caution before offering or administering an influenza vaccine to patients suffering from cancer following a recent patient safety incident.

The NHS England Flu PGD specifies “a weakened immune system due to disease (such as HIV/AIDS) or treatment (such as cancer treatment)” as an inclusion criterion. However when deciding whether an individual patient is eligible for a flu vaccine pharmacists are advised to consider that not all forms of cancer treatment result in a compromised immune system.

A recent safety incident, reported through NRLS and the Yellow Card Scheme, involved a patient diagnosed with a form of bladder cancer. The patient was asked whether they were receiving chemotherapy to which they responded yes. The pharmacy proceeded to administer a flu vaccine because of the potential for immunosuppression in patients receiving chemotherapy.

The patient concerned was being treated with a Bacillus Calmette-Guerin (BCG) bladder infusion. There is some evidence that flu vaccines can interfere with this form of treatment and consequently administration of a flu vaccine is not recommended for 6 weeks before or after treatment with BCG. The administration of the flu vaccine resulted in the hospital postponing the patient’s cancer treatment.

BCG infusion is used for the treatment of superficial bladder cancers, i.e. cancer affecting only the inner surface of the bladder wall but having the potential to progress to a more invasive disease.  BCG infusion is described as “immunotherapy” rather than chemotherapy and is not associated with immunosuppression. Immunotherapy is thought to trigger a local inflammatory reaction which stimulates the immune system to destroy the cancer cells.

As immunotherapy does not result in a compromised immune system or immunosuppression administration of the flu vaccine would not be covered by the NHS Flu PGD and in this case resulted in a delay to the patient’s treatment.