liver cirrhosis (Child-Pugh class B and C).significant heart disease (congenital or acquired) and are pregnant.an absent spleen or have had their spleen removed.rare diseases, including all forms of interstitial lung disease/sarcoidosis, and inborn errors of metabolism (such as SCID and homozygous sickle cell) that significantly increase the risk of infections.severe chest conditions such as cystic fibrosis, severe asthma, severe COPD, severe bronchiectasis and pulmonary hypertension.cancers of the blood or bone marrow, such as leukaemia, lymphoma or myeloma who are at any stage of treatment.lung cancer and are either receiving or previously received radical radiotherapy.cancer and are receiving active chemotherapy.
