From above mentioned patients and healthy volunteers, a maximum of 90 ml of blood will be drawn to analyze DNA methylation patterns of purified monocytes and neutrophils, which will be analyzed in connection with DNA methyltransferase and ten eleven translocation (TET) activity, RNA gene expression and a selection of standard innate immune function tests. Moreover, isolated monocytes and neutrophils from admission samples will be stimulated in vitro with Streptococcus pneumoniae and Klebsiella pneumoniae. In addition, rectal and nasopharyngeal swabs will be obtained to investigate the role of the gut and respiratory microbiota composition and function. Patient material will be obtained upon inclusion and on day 28, when patients will be seen in the outpatient clinic for follow up.