Cystic fibrosis (CF) is an autosomal recessive genetic condition caused by mutations in the gene encoding the CF transmembrane regulator (CFTR) that affects around 10 000 people in the UK.1, 2 CF is a multisystem condition1 but lungs are the main organ affected, with CFTR dysfunction causing abnormal airway surface liquid.1, 3 People with CF are particularly susceptible to infection causing acute deterioration in lung health (i.e. pulmonary exacerbations), which leads to progressive lung damage and eventually respiratory failure.4 This evidence concerns the gene CFTR and infection.